Year : 
2019
Title : 
Mathematics (Core)
Exam : 
JAMB Exam

Paper 1 | Objectives

1 - 10 of 80 Questions

# Question Ans
1.

Make q the subject of the formula in the equation \(\frac{mn}{a^2} - \frac{pq}{b^2} = 1\)

A. \(q = \frac{b^2(mn - a^2)}{a^2 p}\)

B. \(q = \frac{m^2 n - a^2}{p^2}\)

C. \(q = \frac{mn - 2b^2}{a^2}\)

D. \(q = \frac{b^2 (n^2 - ma^2)}{n}\)

Detailed Solution

\(\frac{mn}{a^2} - \frac{pq}{b^2} = 1\)
\(\frac{mn}{a^2} - 1 = \frac{pq}{b^2}\)
\(\frac{mn - a^2}{a^2} = \frac{pq}{b^2}\)
\(pq = \frac{b^2 (mn - a^2)}{a^2}\)
\(q = \frac{b^2(mn - a^2)}{a^2 p}\)
There is an explanation video available below.
2.

The angle of elevation of the top of a tree from a point on the ground 60m away from the foot of the tree is 78°. Find the height of the tree correct to the nearest whole number.

A. 148m

B. 382m

C. 282m

D. 248m

Detailed Solution


\(\tan 78 = \frac{h}{60}\)
\(h = 60 \tan 78\)
\(h = 60 \times 4.705 = 282.27m\)
\(\approxeq\) 282m to the nearest whole number.
There is an explanation video available below.
3.

A binary operation \(\otimes\) is defined by \(m \otimes n = mn + m - n\) on the set of real numbers, for all m, n \(\in\) R. Find the value of 3 \(\otimes\) (2 \(\otimes\) 4).

A. 6

B. 25

C. 15

D. 18

Detailed Solution

\(m \otimes n = mn + m - n\)
3 \(\otimes\) (2 \(\otimes\) 4)
2 \(\otimes\) 4 = 2(4) + 2 - 4 = 6
3 \(otimes\) 6 = 3(6) + 3 - 6 = 15
There is an explanation video available below.
4.

Table:
The table above shows the number of pupils in a class with respect to their ages. If a pie chart is constructed to represent the age, the angle corresponding to 8 years old is

A. 48.6°

B. 56.3°

C. 46.8°

D. 13°

Detailed Solution

Total number of pupils : 4 + 13 + 30 + 44 + 9 = 100
The number of 8 - year olds = 13
The angle represented by the 8-year olds on the pie chart = \(\frac{13}{100} \times 360°\)
= 46.8°
There is an explanation video available below.
5.

In a class of 50 students, 40 students offered Physics and 30 offered Biology. How many offered both Physics and Biology?

A. 42

B. 20

C. 70

D. 54

Detailed Solution

n(Total) = 50
n(Physics) = 40
n(Biology) = 30
Let n(Physics and Biology) = x
n(Physics only) = 40 -x
n(Biology only) = 30 - x
40 - x + 30 - x + x = 50
70 - x = 50
x = 20
There is an explanation video available below.
6.

Rationalize \(\frac{\sqrt{2} + \sqrt{3}}{\sqrt{2} - \sqrt{3}}\)

A. \(-5 - 2\sqrt{6}\)

B. \(-5 + 3\sqrt{2}\)

C. \(5 - 2\sqrt{3}\)

D. \(5 + 2\sqrt{6}\)

Detailed Solution

\(\frac{\sqrt{2} + \sqrt{3}}{\sqrt{2} - \sqrt{3}}\)
= \((\frac{\sqrt{2} + \sqrt{3}}{\sqrt{2} - \sqrt{3}})(\frac{\sqrt{2} + \sqrt{3}}{\sqrt{2} + \sqrt{3}})\)
= \(\frac{2 + \sqrt{6} + \sqrt{6} + 3}{2 - \sqrt{6} + \sqrt{6} - 3}\)
= \(\frac{5 + 2\sqrt{6}}{-1}\)
= \(- 5 - 2\sqrt{6}\)
There is an explanation video available below.
7.

OPEN_PHOTO Find the length of the chord |AB| in the diagram shown above.

A. 4.2 cm

B. 4.3 cm

C. 3.2 cm

D. 3.4 cm

Detailed Solution

Length of chord = \(2r \sin (\frac{\theta}{2})\)
= \(2(3) \sin (\frac{68}{2})\)
= \(6 \sin 34\)
= \(6 \times 0.559\)
= 3.354 cm \(\approxeq\) 3.4 cm
There is an explanation video available below.
8.

Given \(\sin 58° = \cos p°\), find p.

A. 48°

B. 58°

C. 32°

D. 52°

Detailed Solution

\(\sin \theta = \cos (90 - \theta)\)
\(\sin \theta = \cos (90 - 58)\)
= \(\cos 32\)
There is an explanation video available below.
9.

\(\frac{\frac{2}{3} \div \frac{4}{5}}{\frac{1}{4} + \frac{3}{5} - \frac{1}{3}}\)

A. \(\frac{31}{50}\)

B. \(\frac{20}{31}\)

C. \(\frac{31}{20}\)

D. \(\frac{50}{31}\)

Detailed Solution

\(\frac{\frac{2}{3} \div \frac{4}{5}}{\frac{1}{4} + \frac{3}{5} - \frac{1}{3}}\)
\(\frac{2}{3} \div \frac{4}{5} = \frac{2}{3} \times \frac{5}{4}\)
= \(\frac{5}{6}\)
\(\frac{1}{4} + \frac{3}{5} - \frac{1}{3} = \frac{15 + 36 - 20}{60}\)
= \(\frac{31}{60}\)
\(\therefore \frac{\frac{2}{3} \div \frac{4}{5}}{\frac{1}{4} + \frac{3}{5} - \frac{1}{3}} = \frac{5}{6} \div \frac{31}{60}\)
= \(\frac{5}{6} \times \frac{60}{31}\)
= \(\frac{50}{31}\)
There is an explanation video available below.
10.

If \(6x^3 + 2x^2 - 5x + 1\) divides \(x^2 - x - 1\), find the remainder.

A. 9x + 9

B. 2x + 6

C. 6x + 8

D. 5x - 3

Detailed Solution


There is an explanation video available below.
1.

Make q the subject of the formula in the equation \(\frac{mn}{a^2} - \frac{pq}{b^2} = 1\)

A. \(q = \frac{b^2(mn - a^2)}{a^2 p}\)

B. \(q = \frac{m^2 n - a^2}{p^2}\)

C. \(q = \frac{mn - 2b^2}{a^2}\)

D. \(q = \frac{b^2 (n^2 - ma^2)}{n}\)

Detailed Solution

\(\frac{mn}{a^2} - \frac{pq}{b^2} = 1\)
\(\frac{mn}{a^2} - 1 = \frac{pq}{b^2}\)
\(\frac{mn - a^2}{a^2} = \frac{pq}{b^2}\)
\(pq = \frac{b^2 (mn - a^2)}{a^2}\)
\(q = \frac{b^2(mn - a^2)}{a^2 p}\)
There is an explanation video available below.
2.

The angle of elevation of the top of a tree from a point on the ground 60m away from the foot of the tree is 78°. Find the height of the tree correct to the nearest whole number.

A. 148m

B. 382m

C. 282m

D. 248m

Detailed Solution


\(\tan 78 = \frac{h}{60}\)
\(h = 60 \tan 78\)
\(h = 60 \times 4.705 = 282.27m\)
\(\approxeq\) 282m to the nearest whole number.
There is an explanation video available below.
3.

A binary operation \(\otimes\) is defined by \(m \otimes n = mn + m - n\) on the set of real numbers, for all m, n \(\in\) R. Find the value of 3 \(\otimes\) (2 \(\otimes\) 4).

A. 6

B. 25

C. 15

D. 18

Detailed Solution

\(m \otimes n = mn + m - n\)
3 \(\otimes\) (2 \(\otimes\) 4)
2 \(\otimes\) 4 = 2(4) + 2 - 4 = 6
3 \(otimes\) 6 = 3(6) + 3 - 6 = 15
There is an explanation video available below.
4.

Table:
The table above shows the number of pupils in a class with respect to their ages. If a pie chart is constructed to represent the age, the angle corresponding to 8 years old is

A. 48.6°

B. 56.3°

C. 46.8°

D. 13°

Detailed Solution

Total number of pupils : 4 + 13 + 30 + 44 + 9 = 100
The number of 8 - year olds = 13
The angle represented by the 8-year olds on the pie chart = \(\frac{13}{100} \times 360°\)
= 46.8°
There is an explanation video available below.
5.

In a class of 50 students, 40 students offered Physics and 30 offered Biology. How many offered both Physics and Biology?

A. 42

B. 20

C. 70

D. 54

Detailed Solution

n(Total) = 50
n(Physics) = 40
n(Biology) = 30
Let n(Physics and Biology) = x
n(Physics only) = 40 -x
n(Biology only) = 30 - x
40 - x + 30 - x + x = 50
70 - x = 50
x = 20
There is an explanation video available below.
6.

Rationalize \(\frac{\sqrt{2} + \sqrt{3}}{\sqrt{2} - \sqrt{3}}\)

A. \(-5 - 2\sqrt{6}\)

B. \(-5 + 3\sqrt{2}\)

C. \(5 - 2\sqrt{3}\)

D. \(5 + 2\sqrt{6}\)

Detailed Solution

\(\frac{\sqrt{2} + \sqrt{3}}{\sqrt{2} - \sqrt{3}}\)
= \((\frac{\sqrt{2} + \sqrt{3}}{\sqrt{2} - \sqrt{3}})(\frac{\sqrt{2} + \sqrt{3}}{\sqrt{2} + \sqrt{3}})\)
= \(\frac{2 + \sqrt{6} + \sqrt{6} + 3}{2 - \sqrt{6} + \sqrt{6} - 3}\)
= \(\frac{5 + 2\sqrt{6}}{-1}\)
= \(- 5 - 2\sqrt{6}\)
There is an explanation video available below.
7.

OPEN_PHOTO Find the length of the chord |AB| in the diagram shown above.

A. 4.2 cm

B. 4.3 cm

C. 3.2 cm

D. 3.4 cm

Detailed Solution

Length of chord = \(2r \sin (\frac{\theta}{2})\)
= \(2(3) \sin (\frac{68}{2})\)
= \(6 \sin 34\)
= \(6 \times 0.559\)
= 3.354 cm \(\approxeq\) 3.4 cm
There is an explanation video available below.
8.

Given \(\sin 58° = \cos p°\), find p.

A. 48°

B. 58°

C. 32°

D. 52°

Detailed Solution

\(\sin \theta = \cos (90 - \theta)\)
\(\sin \theta = \cos (90 - 58)\)
= \(\cos 32\)
There is an explanation video available below.
9.

\(\frac{\frac{2}{3} \div \frac{4}{5}}{\frac{1}{4} + \frac{3}{5} - \frac{1}{3}}\)

A. \(\frac{31}{50}\)

B. \(\frac{20}{31}\)

C. \(\frac{31}{20}\)

D. \(\frac{50}{31}\)

Detailed Solution

\(\frac{\frac{2}{3} \div \frac{4}{5}}{\frac{1}{4} + \frac{3}{5} - \frac{1}{3}}\)
\(\frac{2}{3} \div \frac{4}{5} = \frac{2}{3} \times \frac{5}{4}\)
= \(\frac{5}{6}\)
\(\frac{1}{4} + \frac{3}{5} - \frac{1}{3} = \frac{15 + 36 - 20}{60}\)
= \(\frac{31}{60}\)
\(\therefore \frac{\frac{2}{3} \div \frac{4}{5}}{\frac{1}{4} + \frac{3}{5} - \frac{1}{3}} = \frac{5}{6} \div \frac{31}{60}\)
= \(\frac{5}{6} \times \frac{60}{31}\)
= \(\frac{50}{31}\)
There is an explanation video available below.
10.

If \(6x^3 + 2x^2 - 5x + 1\) divides \(x^2 - x - 1\), find the remainder.

A. 9x + 9

B. 2x + 6

C. 6x + 8

D. 5x - 3

Detailed Solution


There is an explanation video available below.