WAEC Past Questions and Answers - Page 3865

19,321.

The length, in cm, of the sides of a right angled triangle are x, (x+2) and (x+1) where x > 0. Find , in cm, the length of its hypotenuse

A.

4

B.

5

C.

13

D.

17

Correct answer is B

\((x + 2)^{2} = x^{2} + (x + 1)^{2}\)

\(x^2 + 4x + 4 = x^2 + x^2 + 2x + 1\)

\(2x^{2} - x^{2} + 2x - 4x + 1 - 4 = 0\)

\(x^{2} - 2x - 3 = 0\)

\(x^{2} - 3x + x - 3 = 0 \implies x(x - 3) + 1(x - 3) = 0\)

\((x - 3)(x + 1) = 0 \implies \text{x = 3 or -1}\)

\(x > 0 \implies x = 3\)

The longest side = 3 + 2 = 5.

19,322.

The diagram is the graph of \(y = 6 + x - x^2\). The graph intercepts the x- axis at P and R and the y- axis at Q.

When \(y = 3\frac{1}{3}\), what is the positive value of x?

A.

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

B.

\( 2\frac{1}{5}\)

C.

\( 1\frac{1}{5}\)

D.

0

Correct answer is B

No explanation has been provided for this answer.

19,323.

What is the length of \(\bar{RP}\)?

A.

6

B.

5

C.

3

D.

2

Correct answer is B

\(\bar{RP} = 3 - (-2)\)

= 5

19,324.
19,325.

If \(M5_{ten} = 1001011_{two}\) find the value of M

A.

5

B.

6

C.

7

D.

8

Correct answer is C

\(M5_{ten} = 1001011_{two}\\
=1 \times 2^6 + 0\times 2^5 + 0\times 2^4 + 1\times 2^3 + 0\times 2^2 + 1\times 2^1 \\
=64+8+2+1=75_{ten}\\
∴ m = 7 \)