Year : 
2020
Title : 
Mathematics (Core)
Exam : 
JAMB Exam

Paper 1 | Objectives

11 - 20 of 40 Questions

# Question Ans
11.

If log\(_{10}\)2 = 0.3010 and log\(_{10}\)3 = 0.4771, eventually without using the logarithm tables, log\(_{10}\)4.5

A. 0.3010

B. 0.4771

C. 0.6532

D. 0.9542

Detailed Solution

log\(_{10}\)2 = 0.3010 and log\(_{10}\)3 = 04771
log\(_{10} 4.5 = log_{10}\) (\(\frac{3 \times 3}{2}\))
log\(_{10}\) 3 + log\(_{10}\) 3 - log\(_{10}\)2 = 0.4471 + 0.771 - 0.3010
= 0.6532
There is an explanation video available below.
12.

Simplify \(\frac{324 - 4x^2}{2x + 18}\)

A. 2(x - 9)

B. 2(9 + x)

C. 81 - x\(^2\)

D. -2(x - 9)

Detailed Solution

234 - 4x\(^2\) = 18\(^2\) - (2x)\(^2\) = (18 - 2x)(18 + 2x)
2x + 18 = 2x + 18 = (2x + 18)
18 - 2x = 2(a - x) or -2(x - a)

There is an explanation video available below.
13.

In preparing rice cutlets, a cook used 75g of rice, 40g of margarine, 105g of meat and 20g of bread crumbs. Find the angle of the sector which represent meat in a pie chart?

A. 30\(^o\)

B. 60\(^o\)

C. 112.5\(^o\)

D. 157.5\(^o\)

Detailed Solution

Rice = 75g, Margarine = 40g, Meat = 105g
Bread = 20g
Total = 240
Angle of sector represented by meat
= \(\frac{105}{240} \times \frac{360^o}{1}\)
= 157.5
There is an explanation video available below.
14.

The angle of a sector of a circle radius 10.5 cm is 48\(^o\). Calculate the perimeter of the sector.

A. 25.4cm

B. 25.4cm

C. 25.6cm

D. 29.8cm

Detailed Solution

The lenght of Arc AB = \(\frac{Q}{360}\) 2\(\pi\)r
= \(\frac{48}{360}\) x 2\(\frac{22}{7}\) x 10.5 = \(\frac{48}{360}\) x 2\(\frac{22}{7}\) x \(\frac{21}{2}\)
= \(\frac{4 \times 22 \times 3}{30} \times \frac{88}{10}\) = 8.8cm
Perimeter = 8.8 + 2r = 8.8 + 2r
= 8.8 + 2(10.5)
= 8.8 + 21
= 29.8cm
There is an explanation video available below.
15.

What is the product of \(\frac{27}{5}\), \((3)^{-3}\) and (\(\frac{1}{5})^{-1}\)?

A. 5

B. 3

C. 1

D. \(\frac{1}{25}\)

Detailed Solution

\(\frac{27}{5} \times 3^{-3} \times \frac{(1)^{-1}}{5}\)
= \(\frac{27}{5} \times \frac{1}{3^3} \times \frac{1}{\frac{1}{5}}\)
\(\frac{27}{5}\) x \(\frac{1}{27}\) x \(\frac{5}{1}\) = 1
There is an explanation video available below.
16.

A crate of soft drinks contains 10 bottle of Coca-Cola 8 of Fanta and 6 of Sprite. If one bottle is selected at random, what is the probability that it is Not a Coca-Cola bottle?

A. \(\frac{5}{12}\)

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

C. \(\frac{3}{4}\)

D. \(\frac{7}{12}\)

Detailed Solution

Coca-Cola = 10 bottles, Fanta = 8 bottles, Spirite = 6 bottles
Total = 24
P(Coca-Cola) = \(\frac{10}{24}\); P(not Coca-Cola)
1 - \(\frac{10}{24}\)
\(\frac{24 - 10}{24} = \frac{14}{24} = \frac{7}{12}\)
There is an explanation video available below.
17.

In this fiqure, PQ = PR = PS and SRT = 68\(^o\). Find QPS

A. 136\(^o\)

B. 124\(^o\)

C. 112\(^o\)

D. 68\(^o\)

Detailed Solution

Since PQRS is quadrilateral
2y + 2x + QPS = 360\(^o\)
i.e. (y + x) + QPS = 360\(^o\)
QPS = 360\(^o\) - 2 (y + x)
But x + y + 68\(^o\) = 180\(^o\)
There; x + y = 180\(^o\) - 68\(^o\) = 112\(^o\)
QPS = 360 - 2(112\(^o\))
= 360\(^o\) - 224 = 136\(^o\)
There is an explanation video available below.
18.

Find the gradient of the line passing through the points (-2, 0) and (0, -4)

A. 2

B. -4

C. -2

D. 4

Detailed Solution

Given (-2, 0) ans (0, -4).
Gradient = \(\frac{y_2 - y_1}{x_2 - x_1}\)
= \(\frac{-4 - 0}{0 - (-2)}\)
= \(\frac{-4}{2}\)
= -2
There is an explanation video available below.
19.

Find the equation of the line through the points (5, 7) parallel to the line 7x + 5y = 12.

A. 5x + 7y = 120

B. 7x + 5y = 70

C. x + y = 7

D. 15x + 17y = 90

Detailed Solution

Equation through (5,7) parallel to the line
7x + 5y = 12
5y = 7x + 12
y = \(\frac{-7x}{5} + \frac{12}{5}\)
Gradient = \(\frac{-7}{5}\)
Required equation = \(\frac{y - 7}{x - 5} = \frac{-7}{5}\)
i.e. 5y - 35 = -7x + 35
5y + 7x = 70
There is an explanation video available below.
20.

If N225.00 yields N27.00 in x years simple interest at the rate of 4% per annum, find x.

A. 3

B. 4

C. 12

D. 17

Detailed Solution

Principal = N225.00, interest = N27.00
Year = x, Rate = 4%
1 = \(\frac{PRT}{100}\)
27 = \(\frac{225 \times 4 \times x}{100}\) = 2700 = 900T
T = \(\frac{2700}{900}\)
= 3 years
There is an explanation video available below.
11.

If log\(_{10}\)2 = 0.3010 and log\(_{10}\)3 = 0.4771, eventually without using the logarithm tables, log\(_{10}\)4.5

A. 0.3010

B. 0.4771

C. 0.6532

D. 0.9542

Detailed Solution

log\(_{10}\)2 = 0.3010 and log\(_{10}\)3 = 04771
log\(_{10} 4.5 = log_{10}\) (\(\frac{3 \times 3}{2}\))
log\(_{10}\) 3 + log\(_{10}\) 3 - log\(_{10}\)2 = 0.4471 + 0.771 - 0.3010
= 0.6532
There is an explanation video available below.
12.

Simplify \(\frac{324 - 4x^2}{2x + 18}\)

A. 2(x - 9)

B. 2(9 + x)

C. 81 - x\(^2\)

D. -2(x - 9)

Detailed Solution

234 - 4x\(^2\) = 18\(^2\) - (2x)\(^2\) = (18 - 2x)(18 + 2x)
2x + 18 = 2x + 18 = (2x + 18)
18 - 2x = 2(a - x) or -2(x - a)

There is an explanation video available below.
13.

In preparing rice cutlets, a cook used 75g of rice, 40g of margarine, 105g of meat and 20g of bread crumbs. Find the angle of the sector which represent meat in a pie chart?

A. 30\(^o\)

B. 60\(^o\)

C. 112.5\(^o\)

D. 157.5\(^o\)

Detailed Solution

Rice = 75g, Margarine = 40g, Meat = 105g
Bread = 20g
Total = 240
Angle of sector represented by meat
= \(\frac{105}{240} \times \frac{360^o}{1}\)
= 157.5
There is an explanation video available below.
14.

The angle of a sector of a circle radius 10.5 cm is 48\(^o\). Calculate the perimeter of the sector.

A. 25.4cm

B. 25.4cm

C. 25.6cm

D. 29.8cm

Detailed Solution

The lenght of Arc AB = \(\frac{Q}{360}\) 2\(\pi\)r
= \(\frac{48}{360}\) x 2\(\frac{22}{7}\) x 10.5 = \(\frac{48}{360}\) x 2\(\frac{22}{7}\) x \(\frac{21}{2}\)
= \(\frac{4 \times 22 \times 3}{30} \times \frac{88}{10}\) = 8.8cm
Perimeter = 8.8 + 2r = 8.8 + 2r
= 8.8 + 2(10.5)
= 8.8 + 21
= 29.8cm
There is an explanation video available below.
15.

What is the product of \(\frac{27}{5}\), \((3)^{-3}\) and (\(\frac{1}{5})^{-1}\)?

A. 5

B. 3

C. 1

D. \(\frac{1}{25}\)

Detailed Solution

\(\frac{27}{5} \times 3^{-3} \times \frac{(1)^{-1}}{5}\)
= \(\frac{27}{5} \times \frac{1}{3^3} \times \frac{1}{\frac{1}{5}}\)
\(\frac{27}{5}\) x \(\frac{1}{27}\) x \(\frac{5}{1}\) = 1
There is an explanation video available below.
16.

A crate of soft drinks contains 10 bottle of Coca-Cola 8 of Fanta and 6 of Sprite. If one bottle is selected at random, what is the probability that it is Not a Coca-Cola bottle?

A. \(\frac{5}{12}\)

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

C. \(\frac{3}{4}\)

D. \(\frac{7}{12}\)

Detailed Solution

Coca-Cola = 10 bottles, Fanta = 8 bottles, Spirite = 6 bottles
Total = 24
P(Coca-Cola) = \(\frac{10}{24}\); P(not Coca-Cola)
1 - \(\frac{10}{24}\)
\(\frac{24 - 10}{24} = \frac{14}{24} = \frac{7}{12}\)
There is an explanation video available below.
17.

In this fiqure, PQ = PR = PS and SRT = 68\(^o\). Find QPS

A. 136\(^o\)

B. 124\(^o\)

C. 112\(^o\)

D. 68\(^o\)

Detailed Solution

Since PQRS is quadrilateral
2y + 2x + QPS = 360\(^o\)
i.e. (y + x) + QPS = 360\(^o\)
QPS = 360\(^o\) - 2 (y + x)
But x + y + 68\(^o\) = 180\(^o\)
There; x + y = 180\(^o\) - 68\(^o\) = 112\(^o\)
QPS = 360 - 2(112\(^o\))
= 360\(^o\) - 224 = 136\(^o\)
There is an explanation video available below.
18.

Find the gradient of the line passing through the points (-2, 0) and (0, -4)

A. 2

B. -4

C. -2

D. 4

Detailed Solution

Given (-2, 0) ans (0, -4).
Gradient = \(\frac{y_2 - y_1}{x_2 - x_1}\)
= \(\frac{-4 - 0}{0 - (-2)}\)
= \(\frac{-4}{2}\)
= -2
There is an explanation video available below.
19.

Find the equation of the line through the points (5, 7) parallel to the line 7x + 5y = 12.

A. 5x + 7y = 120

B. 7x + 5y = 70

C. x + y = 7

D. 15x + 17y = 90

Detailed Solution

Equation through (5,7) parallel to the line
7x + 5y = 12
5y = 7x + 12
y = \(\frac{-7x}{5} + \frac{12}{5}\)
Gradient = \(\frac{-7}{5}\)
Required equation = \(\frac{y - 7}{x - 5} = \frac{-7}{5}\)
i.e. 5y - 35 = -7x + 35
5y + 7x = 70
There is an explanation video available below.
20.

If N225.00 yields N27.00 in x years simple interest at the rate of 4% per annum, find x.

A. 3

B. 4

C. 12

D. 17

Detailed Solution

Principal = N225.00, interest = N27.00
Year = x, Rate = 4%
1 = \(\frac{PRT}{100}\)
27 = \(\frac{225 \times 4 \times x}{100}\) = 2700 = 900T
T = \(\frac{2700}{900}\)
= 3 years
There is an explanation video available below.