JAMB Mathematics Past Questions & Answers - Page 341

1,701.

The gradient of a line joining (x,4) and (1,2) is \(\frac{1}{2}\). Find the value of x

A.

5

B.

3

C.

-3

D.

-5

Correct answer is A

\(\text{Gradient m} = \frac{y_2 - y_1}{x_2 - x_1}\)

\(\frac{1}{2} = \frac{2 - 4}{1 - x}\)

1 - x = 2(2 - 4)

1 - x = 4 - 8

1 - x = -4

-x = -4 - 1

x = 5

1,702.

Find the mid point of S(-5, 4) and T(-3, -2)

A.

-4, 2

B.

4, -2

C.

-4, 1

D.

4, -1

Correct answer is C

Mid point of S(-5, 4) and T(-3, -2) is

\([\frac{1}{2}(-5 + -3), \frac{1}{2}(4 + 2)]\)

\([\frac{1}{2}(x_1 + x_2), \frac{1}{2}(y_1 + y_2)]\)

\([\frac{1}{2}(-8), \frac{1}{2}(2)]\)

\([-4, 1]\)

1,703.

A cylindrical tank has a capacity of 6160m3. What is the depth of the tank if the radius of its base is 28cm?

A.

8.0m

B.

7.5m

C.

5.0m

D.

2.5m

Correct answer is D

Using \(V = \pi r^2 h\)

6160 = 22/7 x 28 x 28 x h

\(h = \frac{6160}{22 \times 4 \times 28} \)

\(h = 2.5m \)

1,704.

How many sides has a regular polygon whose interior angle is 135°?

A.

12

B.

10

C.

9

D.

8

Correct answer is D

p>If each interior angle of the polygon is 135°, then each exterior angle is 180° - 135° = 45°.

Hence, number of sides =

\(\frac{360°}{\text{one exterior angle}}\)

\(\frac{360°}{45°}\)

= 8

1,705.

Find the value of \(\begin{vmatrix}0 & 3 & 2 \\1 & 7 & 8 \\0 & 5 & 4\end{vmatrix}\).

A.

12

B.

10

C.

-1

D.

-2

Correct answer is D

\(0 \begin{vmatrix}7 & 8 \\5 & 4\end{vmatrix} -3 \begin{vmatrix}1 & 8 \\0 & 4\end{vmatrix} +2 \begin{vmatrix}1 & 7 \\0 & 5\end{vmatrix}\)

= 0(28 - 40) - 3(4 - 0) + 2(5 - 0)

= 0(-12) - 3(4) + 2(5)

= 0 - 12 + 10

= -2