JAMB Mathematics Past Questions & Answers - Page 373

1,861.

In triangle XYZ, ∠XYZ = 15o, ∠XZY = 45o and lXYl = 7 cm. Find lYZl.

A.

14√2 cm

B.

\(7\left(\frac{\sqrt{6}}{2}\right)\)

C.

7√2 cm

D.

7 cm

Correct answer is B

No explanation has been provided for this answer.

1,862.

PQ and RS are two parallel lines. If the coordinates of P, Q, R, S are (1,q), (3,2), (3,4), (5,2q) respectively, find the value of q

A.

3

B.

4

C.

1

D.

2

Correct answer is D

Gradient PQ, P(1,q) and Q(3,2)
\(=\frac{(2-q)}{(3-1)} = \frac{(2-q)}{2}\)
Gradient of RS : R(3,4) and S(5,2q)
\(= \frac{(2q-4)}{(5-3)}= \frac{(2q-4)}{2} = \frac{2(q-2)}{2}\)
= q-2
Since PQ and RS are parallel,
their gradients are equal
\(∴ \frac{(2-q)}{2} = q-2\)
2-q = 2(q-2)
2-q = 2q-4
2+4 = 2q+q
6 = 3q
q = 2

1,863.

If tan θ = 5/4, find sin2θ - cos2θ.

A.

5/4

B.

41/9

C.

9/41

D.

1

Correct answer is C

No explanation has been provided for this answer.

1,864.

Convert 2232\(_4\) to base six

A.

4506

B.

2546

C.

5536

D.

5406

Correct answer is A

1st convert to base 10
2232\(_4\) = 2 x 4\(^3\) + 2 x 4\(^2\) + 3 x 4\(^1\) + 2 x 4\(^0\)
= 2 x 64 + 2 x 16 + 3 x 4 + 2 x 1
= 128 + 32 + 12 + 2
= 174 convert to base 6
6/174
6/29 R 0
6/4 R 5
6/0 R 4
= 450\(_6\)

1,865.

Simplify \((25)^{\frac{-1}{2}} \times (27)^{\frac{1}{3}} + (121)^{\frac{-1}{2}} \times (625)^{\frac{-1}{4}}\)

A.

34/55

B.

9/11

C.

14/5

D.

3/275

Correct answer is A

(25)\(^{\frac{-1}{2}}\) x (27)\(^{\frac{1}{3}}\) + (121)\(^{\frac{-1}{2}}\) x (625)\(^{\frac{-1}{4}}\)
5\(^{2 \times \frac{-1}{2}}\) x 3\(^{3 \times \frac{1}{3}}\) + 11\(^{2 \times \frac{-1}{2}}\) x 5\(^{4 \times \frac{-1}{4}}\)
5\(^{-1}\) x 3\(^1\) x 11\(^{-1}\) x 5\(^{-1}\)
\(\frac{1}{5} \times \frac{3}{1} + \frac{1}{11} \times \frac{1}{5}\)
\(\frac{3}{5} + \frac{1}{55} = \frac{33+1}{55}\)
= \(\frac{34}{55}\)