WAEC Mathematics Past Questions & Answers - Page 114

566.

Simplify; \(\frac{3\sqrt{5} \times 4\sqrt{6}}{2 \sqrt{3} \times 3\sqrt{2}}\)

A.

\(\sqrt{2}\)

B.

\(\sqrt{5}\)

C.

2\(\sqrt{2}\)

D.

2\(\sqrt{5}\)

Correct answer is D

\(\frac{3\sqrt{5} \times 4\sqrt{6}}{2 \sqrt{3} \times 3\sqrt{2}}\)

= \(\frac{\sqrt{5} \times 2\sqrt{6}}{\sqrt{2} \times \sqrt{3}}\)

= \(\frac{\sqrt{5} \times 2 \sqrt{6}}{\sqrt{6}}\)

= 2\(\sqrt{5}\)

567.

Express 302.10495 correct to five significant figures

A.

302.10

B.

302.11

C.

302.105

D.

302.1049

Correct answer is A

No explanation has been provided for this answer.

568.

In the diagram /Pq//TS//TU, reflex angle QPS = 245o angle PST = 115o, , STU = 65o and < RPS = x. Find the value of x

A.

80o

B.

70o

C.

60o

D.

50o

Correct answer is D

< QPR = < STU = 65o (Corresponding angles)

245 + < QPR = x = 360o (< s at a point)

i.e. 245 + 65 + x = 360

x = 360 - (245 + 65)

x = 360 - 310

x = 50o

569.

The venn diagram shows the number of students in a class who like reading(R), dancing(D) and swimming(S). How many students like dancing and swimming?

A.

7

B.

9

C.

11

D.

13

Correct answer is A

student that like swimming = x + 2

where 2 is the number of students who like reading, dancing and swimming. To find x from the venn diagram of swimming

6 +3 + 2 + x = 16

11 + x = 16

x = 16 - 11 = 5

no. of students that like dancing and swimming

x + 2 = 5 + 2 = 7

570.

In the diagram, STUV is a straight line. < TSY = < UXY = 40o and < VUW = 110o. Calculate < TYW

A.

150o

B.

140o

C.

130o

D.

120o

Correct answer is A

< TUW = 110o = 180o (< s on a straight line)

< TUW = 180o - 110o = 70o

In \(\bigtriangleup\) XTU, < XUT + < TXU = 180o

i.e. < YTS + 70o = 180

< XTU = 180 - 110o = 70o

Also < YTS + < XTU = 180 (< s on a straight line)

i.e. < YTS + < XTU - 180(< s on straight line)

i.e. < YTS + 70o = 180

< YTS = 180 - 70 = 110o

in \(\bigtriangleup\) SYT + < YST + < YTS = 180o(Sum of interior < s)

SYT + 40 + 110 = 180

< SYT = 180 - 150 = 30

< SYT = < XYW (vertically opposite < s)

Also < SYX = < TYW (vertically opposite < s)

but < SYT + < XYW + < SYX + < TYW = 360

i.e. 30 + 30 + < SYX + TYW = 360

but < SYX = < TYW

60 + 2(< TYW) = 360

2(< TYW) = 360o - 60

2(< TYW) = 300o

TYW = \(\frac{300}{2}\) = 150o
< SYT