WAEC Mathematics Past Questions & Answers - Page 117

581.

A rectangular garden measures 18.6m by 12.5m. Calculate, correct to three significant figures, the area of the garden

A.

230m2

B.

231m2

C.

232m2

D.

233m2

Correct answer is D

A = L x B

= (18.6 x 12.5)m2

= 232.5m2

= 233m2

582.

The perpendicular bisectors of the sides of an acute-angled triangle are drawn. Which of these statements is correct? They intersect

A.

on one of the vertices

B.

at a midpoint of a side

C.

inside the triangle

D.

outside the triangle

Correct answer is C

No explanation has been provided for this answer.

583.

Find the smaller value of x that satisfies the equation x2 + 7x + 10 = 0

A.

-5

B.

-2

C.

2

D.

5

Correct answer is A

x2 + 7x + 10 = 0

x2 + 5x + 2x + 10 = 0

x(x + 5) + 2(x + 5) = 0

(x + 2)(x + 5) = 0

x + 2 = 0 or x + 5 = 0

x = -2 or x = -5

the smaller value x = -5x2 + 7x + 10 = 0

x2 + 5x + 2x + 10 = 0

x(x + 5) + 2(x + 5) = 0

(x + 2)(x + 5) = 0

x + 2 = 0 or x + 5 = 0

x = -2 or x = -5

the smaller value x = -5

584.

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

A.

3\(\frac{5}{12}\)

B.

2\(\frac{7}{12}\)

C.

-4 \(\frac{7}{12}\)

D.

-5 \(\frac{7}{12}\)

Correct answer is C

1\(\frac{3}{4} - (2 \frac{1}{3} + 4)\) = \(\frac{7}{4} - (\frac{7}{3} + \frac{4}{1})\); \(\frac{7 + 12}{3}\)

\(\frac{7}{4} - \frac{19}{3} = \frac{21 + 76}{12}\)


= \(\frac{-55}{12} = -4 \frac{7}{12}\)

585.

What must be added to (2x - 3y) to get (x - 2y)?

A.

5y - x

B.

y - x

C.

x - 5x

D.

x - y

Correct answer is B

What must be added to 2x - 3y = Difference between x - 2y and 2x - 3y

x - 2y - 2y - (2x - 3y); x - 2y - 2x + 3y

= x - 2x + 3y - 2y

= y - x