Year : 
1984
Title : 
Mathematics (Core)
Exam : 
JAMB Exam

Paper 1 | Objectives

1 - 10 of 45 Questions

# Question Ans
1.

Simplify \(\frac{(\frac{2}{3} - \frac{1}{5}) - \frac{1}{3} \text{of} \frac{2}{5}}{3 - \frac{1}{1 \frac{1}{2}}}\)

A. \(\frac{1}{7}\)

B. 7

C. \(\frac{1}{3}\)

D. 3

Detailed Solution

\(\frac{2}{3} - \frac{1}{5}\) = \(\frac{10 - 3}{15}\)

= \(\frac{7}{15}\)

\(\frac{1}{3}\) Of \(\frac{2}{5}\) = \(\frac{1}{3}\) x \(\frac{2}{5}\)

= \(\frac{2}{15}\)

(\(\frac{2}{3} - \frac{1}{5}\)) - \(\frac{1}{3}\) of \(\frac{2}{5}\)

= \(\frac{7}{15} - \frac{2}{15}\) = \(\frac{1}{3}\)

3 - \(\frac{1}{1 \frac{1}{2}}\) = 3 - \(\frac{2}{3}\)

= \(\frac{7}{3}\)

\(\frac{\frac{2}{3} - \frac{1}{5} \text{of} \frac{2}{15}}{3 - \frac{1}{1 \frac{1}{2}}}\)

= \(\frac{\frac{1}{3}}{\frac{7}{3}}\)

= \(\frac{1}{3}\)
2.

\(\frac{0.0001432}{1940000}\) = k x 10n where 1 \(\leq\) k < 10 and n is a whole number. The values K and n are

A. 7.381 qnd -11

B. 2.34 and 10

C. 3.871 and 2

D. 7.831 and -11

Detailed Solution

\(\frac{0.0001432}{1940000}\) = k x 10n

where 1 \(\leq\) k \(\leq\) 10 and n is a whole number. Using four figure tables, the eqn. gives 7.38 x 10-11

k = 7.381, n = -11
3.

P sold his bicycle to Q at a profit of 10%. Q sold it to R for N209 at a loss of 5%. How much did the bicycle cost P?

A. N200

B. N196

C. N180

D. N205

E. N150

Detailed Solution

Let the selling price(SP from P to Q be represented by x

i.e. SP = x

When SP = x at 10% profit

CP = \(\frac{100}{100}\) + 10 of x = \(\frac{100}{110}\) of x

when Q sells to R, SP = N209 at loss of 5%

Q's cost price = Q's selling price

CP = \(\frac{100}{95}\) x 209

= 220.00

x = 220

= \(\frac{2200}{11}\)

= 200

= N200.00
4.

If the price of oranges was raised by \(\frac{1}{2}\)k per orange. The number of oranges a customer can buy for N2.40 will be less by 16. What is the present price of an orange?

A. 2\(\frac{1}{2}\)

B. \(\frac{2}{15}\)

C. 5\(\frac{1}{3}\)

D. 20

Detailed Solution

Let x represent the price of an orange and

y represent the number of oranges that can be bought

xy = 240k, y = \(\frac{240}{x}\).....(i)

If the price of an oranges is raised by \(\frac{1}{2}\)k per orange, number that can be bought for N240 is reduced by 16

Hence, y - 16 = \(\frac{240}{x + \frac{1}{2}\)

= \(\frac{480}{2x + 1}\)

= \(\frac{480}{2x + 1}\).....(ii)

subt. for y in eqn (ii) \(\frac{240}{x}\) - 16

= \(\frac{480}{2x + 1}\)

= \(\frac{240 - 16x}{x}\)

= \(\frac{480}{2x + 1}\)

= (240 - 16x)(2x + 1)
5.

A man invested a total of N50000 in two companies. If these companies pay dividends of 6% and 8% respectively, how much did he invest at 8% if the total yield is N3700?

A. N15 000

B. N29 600

C. N27 800

D. N21 400

E. N35 000

Detailed Solution

Total yield = N3,700

Total amount invested = N 50,000

Let x be the amount invested at 6% interest and let y be the amount invested at 8% interest

then yield on x = \(\frac{6}{100}\) x and yield on y = \(\frac{8}{100}\)y

Hence, \(\frac{6}{100}\)x + \(\frac{8}{100}\)y

= 3,700.........(i)

x + y = 50,000........(ii)

6x + 8y = 370,000 x 1

x + y = 50,000 x 6

6x + 8y = 370,000.........(iii)

6x + 6y = 300,000........(iv)

eqn (iii) - eqn(2)

2y = 70,000<
6.

Thirty boys and x girls sat for a rest. The mean of the boys scores and that of the girls were respectively 6 and 8. Find x if the total scores was 468

A. 38

B. 24

C. 36

D. 22

E. 41

Detailed Solution

Number of boy's = 30

Number of girls = x

Mean of boys' score = 6, for girls = 8

Total score for boys = 30 x 6

Total score for both boys and girls = 468

180 + 8x = 468

x = \(\frac{288}{8}\)

= 36
7.

The cost of production of an article is made up as follows: Labour N70, Power N15, Materials N30, Miscellaneous N5. Find the angle of the sector representing Labour in a pie chart

A. 210o

B. 105o

C. 105o

D. 175o

E. 90o

Detailed Solution

Total cost of production = N120.00

Labour Cost = \(\frac{70}{120}\) x \(\frac{360^o}{1}\)

= 210o
8.

Bola choose at random a number between 1 and 300. What is the probability that the number is divisible by 4?

A. \(\frac{1}{4}\)

B. \(\frac{4}{4}\)

C. \(\frac{6}{4}\)

D. \(\frac{7}{4}\)

E. \(\frac{37}{149}\)

Detailed Solution

Numbers divisible by 4 between 1 and 300 include 4, 8, 12, 16, 20 e.t.c.To get the number of figures divisible by 4, We solve by method of A.P

Let x represent numbers divisible by 4, nth term = a + (n - 1)d

a = 4, d = 4

Last term = 4 + (n - 1)4

296 = 4 + 4n - 4

= \(\frac{296}{4}\)

= 74
rn(Note: 296 is the last Number divisible by 4 between 1 and 300)

Prob. of x = \(\frac{74}{298}\)

= \(\frac{37}{149}\)
9.

Find, without using logarithm tables, the value of \(\frac{log_3 27 - log_{\frac{1}{4}} 64}{log_3 \frac{1}{81}}\)

A. \(\frac{-3}{9}\)

B. \(\frac{-3}{2}\)

C. \(\frac{6}{11}\)

D. \(\frac{43}{78}\)

Detailed Solution

\(\frac{\log_{3} 27 - \log_{\frac{1}{4}} 64}{\log_{3} (\frac{1}{81})}\)
\(\log_{3} 27 = \log_{3} 3^{3} = 3\log_{3} 3 = 3\)
\(\log_{\frac{1}{4}} 64 = \log_{\frac{1}{4}} (\frac{1}{4})^{-3} = -3\)
\(\log_{3} (\frac{1}{81}) = \log_{3} 3^{-4} = -4\)
\(\therefore \frac{\log_{3} 27 - \log_{\frac{1}{4}} 64}{\log_{3} (\frac{1}{81})} = \frac{3 - (-3)}{-4}\)
= \(\frac{6}{-4} = \frac{-3}{2}\)
10.

A variable point p(x, y) traces a graph in a two-dimensional plane. (0, 3) is one position of P. If x increases by 1 unit, y increases by 4 units. The equation of the graph is

A. -3 = \(\frac{y + 4}{x + 1}\)

B. 4y = -3 + x

C. \(\frac{y}{x}\) = \(\frac{-3}{4}\)

D. 4x = y + 3

Detailed Solution

P(x, y), P(0, 3) If x increases by 1 unit and y by 4 units, then ratio of x : y = 1 : 4

\(\frac{x}{1}\) = \(\frac{y}{4}\)

y = 4x

Hence the sign of the graph is y + 3 = 4x
1.

Simplify \(\frac{(\frac{2}{3} - \frac{1}{5}) - \frac{1}{3} \text{of} \frac{2}{5}}{3 - \frac{1}{1 \frac{1}{2}}}\)

A. \(\frac{1}{7}\)

B. 7

C. \(\frac{1}{3}\)

D. 3

Detailed Solution

\(\frac{2}{3} - \frac{1}{5}\) = \(\frac{10 - 3}{15}\)

= \(\frac{7}{15}\)

\(\frac{1}{3}\) Of \(\frac{2}{5}\) = \(\frac{1}{3}\) x \(\frac{2}{5}\)

= \(\frac{2}{15}\)

(\(\frac{2}{3} - \frac{1}{5}\)) - \(\frac{1}{3}\) of \(\frac{2}{5}\)

= \(\frac{7}{15} - \frac{2}{15}\) = \(\frac{1}{3}\)

3 - \(\frac{1}{1 \frac{1}{2}}\) = 3 - \(\frac{2}{3}\)

= \(\frac{7}{3}\)

\(\frac{\frac{2}{3} - \frac{1}{5} \text{of} \frac{2}{15}}{3 - \frac{1}{1 \frac{1}{2}}}\)

= \(\frac{\frac{1}{3}}{\frac{7}{3}}\)

= \(\frac{1}{3}\)
2.

\(\frac{0.0001432}{1940000}\) = k x 10n where 1 \(\leq\) k < 10 and n is a whole number. The values K and n are

A. 7.381 qnd -11

B. 2.34 and 10

C. 3.871 and 2

D. 7.831 and -11

Detailed Solution

\(\frac{0.0001432}{1940000}\) = k x 10n

where 1 \(\leq\) k \(\leq\) 10 and n is a whole number. Using four figure tables, the eqn. gives 7.38 x 10-11

k = 7.381, n = -11
3.

P sold his bicycle to Q at a profit of 10%. Q sold it to R for N209 at a loss of 5%. How much did the bicycle cost P?

A. N200

B. N196

C. N180

D. N205

E. N150

Detailed Solution

Let the selling price(SP from P to Q be represented by x

i.e. SP = x

When SP = x at 10% profit

CP = \(\frac{100}{100}\) + 10 of x = \(\frac{100}{110}\) of x

when Q sells to R, SP = N209 at loss of 5%

Q's cost price = Q's selling price

CP = \(\frac{100}{95}\) x 209

= 220.00

x = 220

= \(\frac{2200}{11}\)

= 200

= N200.00
4.

If the price of oranges was raised by \(\frac{1}{2}\)k per orange. The number of oranges a customer can buy for N2.40 will be less by 16. What is the present price of an orange?

A. 2\(\frac{1}{2}\)

B. \(\frac{2}{15}\)

C. 5\(\frac{1}{3}\)

D. 20

Detailed Solution

Let x represent the price of an orange and

y represent the number of oranges that can be bought

xy = 240k, y = \(\frac{240}{x}\).....(i)

If the price of an oranges is raised by \(\frac{1}{2}\)k per orange, number that can be bought for N240 is reduced by 16

Hence, y - 16 = \(\frac{240}{x + \frac{1}{2}\)

= \(\frac{480}{2x + 1}\)

= \(\frac{480}{2x + 1}\).....(ii)

subt. for y in eqn (ii) \(\frac{240}{x}\) - 16

= \(\frac{480}{2x + 1}\)

= \(\frac{240 - 16x}{x}\)

= \(\frac{480}{2x + 1}\)

= (240 - 16x)(2x + 1)
5.

A man invested a total of N50000 in two companies. If these companies pay dividends of 6% and 8% respectively, how much did he invest at 8% if the total yield is N3700?

A. N15 000

B. N29 600

C. N27 800

D. N21 400

E. N35 000

Detailed Solution

Total yield = N3,700

Total amount invested = N 50,000

Let x be the amount invested at 6% interest and let y be the amount invested at 8% interest

then yield on x = \(\frac{6}{100}\) x and yield on y = \(\frac{8}{100}\)y

Hence, \(\frac{6}{100}\)x + \(\frac{8}{100}\)y

= 3,700.........(i)

x + y = 50,000........(ii)

6x + 8y = 370,000 x 1

x + y = 50,000 x 6

6x + 8y = 370,000.........(iii)

6x + 6y = 300,000........(iv)

eqn (iii) - eqn(2)

2y = 70,000<
6.

Thirty boys and x girls sat for a rest. The mean of the boys scores and that of the girls were respectively 6 and 8. Find x if the total scores was 468

A. 38

B. 24

C. 36

D. 22

E. 41

Detailed Solution

Number of boy's = 30

Number of girls = x

Mean of boys' score = 6, for girls = 8

Total score for boys = 30 x 6

Total score for both boys and girls = 468

180 + 8x = 468

x = \(\frac{288}{8}\)

= 36
7.

The cost of production of an article is made up as follows: Labour N70, Power N15, Materials N30, Miscellaneous N5. Find the angle of the sector representing Labour in a pie chart

A. 210o

B. 105o

C. 105o

D. 175o

E. 90o

Detailed Solution

Total cost of production = N120.00

Labour Cost = \(\frac{70}{120}\) x \(\frac{360^o}{1}\)

= 210o
8.

Bola choose at random a number between 1 and 300. What is the probability that the number is divisible by 4?

A. \(\frac{1}{4}\)

B. \(\frac{4}{4}\)

C. \(\frac{6}{4}\)

D. \(\frac{7}{4}\)

E. \(\frac{37}{149}\)

Detailed Solution

Numbers divisible by 4 between 1 and 300 include 4, 8, 12, 16, 20 e.t.c.To get the number of figures divisible by 4, We solve by method of A.P

Let x represent numbers divisible by 4, nth term = a + (n - 1)d

a = 4, d = 4

Last term = 4 + (n - 1)4

296 = 4 + 4n - 4

= \(\frac{296}{4}\)

= 74
rn(Note: 296 is the last Number divisible by 4 between 1 and 300)

Prob. of x = \(\frac{74}{298}\)

= \(\frac{37}{149}\)
9.

Find, without using logarithm tables, the value of \(\frac{log_3 27 - log_{\frac{1}{4}} 64}{log_3 \frac{1}{81}}\)

A. \(\frac{-3}{9}\)

B. \(\frac{-3}{2}\)

C. \(\frac{6}{11}\)

D. \(\frac{43}{78}\)

Detailed Solution

\(\frac{\log_{3} 27 - \log_{\frac{1}{4}} 64}{\log_{3} (\frac{1}{81})}\)
\(\log_{3} 27 = \log_{3} 3^{3} = 3\log_{3} 3 = 3\)
\(\log_{\frac{1}{4}} 64 = \log_{\frac{1}{4}} (\frac{1}{4})^{-3} = -3\)
\(\log_{3} (\frac{1}{81}) = \log_{3} 3^{-4} = -4\)
\(\therefore \frac{\log_{3} 27 - \log_{\frac{1}{4}} 64}{\log_{3} (\frac{1}{81})} = \frac{3 - (-3)}{-4}\)
= \(\frac{6}{-4} = \frac{-3}{2}\)
10.

A variable point p(x, y) traces a graph in a two-dimensional plane. (0, 3) is one position of P. If x increases by 1 unit, y increases by 4 units. The equation of the graph is

A. -3 = \(\frac{y + 4}{x + 1}\)

B. 4y = -3 + x

C. \(\frac{y}{x}\) = \(\frac{-3}{4}\)

D. 4x = y + 3

Detailed Solution

P(x, y), P(0, 3) If x increases by 1 unit and y by 4 units, then ratio of x : y = 1 : 4

\(\frac{x}{1}\) = \(\frac{y}{4}\)

y = 4x

Hence the sign of the graph is y + 3 = 4x