WAEC Mathematics Past Questions & Answers - Page 236

1,176.

A group of 11 people can speak either English or French or Both. Seven can speak English and six can speak French. What is the probability that a person chosen at random can speak both English and French?

A.

\(\frac{2}{11}\)

B.

\(\frac{4}{11}\)

C.

\(\frac{5}{11}\)

D.

\(\frac{11}{13}\)

Correct answer is A

Let the number of people that speak both English and French = x

Then (7 - x) + x + (6 - x) = 11

13 - x = 11 \(\implies\) x = 2.

\(\therefore\) P(picking a person that speaks both languages) = 2/11

1,177.

The pie chart illustrate the amount of private time a student spends in a week studying various subjects. use it to answer the question below

If he sends \(2\frac{1}{2}\) hours week on science, find the total number of hours he studies in a week

A.

\(3\frac{1}{3}\) hours

B.

5 hours

C.

8 hours

D.

12 hours

Correct answer is D

Let x represent the total number of hours spent per week

\(∴ \frac{75}{360} \times x = \frac{5}{2}\)

\(∴ x = \frac{360 \times 5}{725 \times 2}=12 hours\)

1,178.

The pie chart illustrate the amount of private time a student spends in a week studying various subjects. use it to answer the question below Find the value of K

A.

15o

B.

30o

C.

60o

D.

90o

Correct answer is B

Total angle in a circle = 360°

\(\therefore\) 105 + 75 + 2k + k + 3k = 360°

6k = 360 - 180 = 180

k = 180/6 = 30°

1,179.

From a set \(A = [3, \sqrt{2}, 2\sqrt{3}, \sqrt{9}, \sqrt{7}]\), a number is selected at random. Find the probability that is a rational number

A.

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

B.

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

C.

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

D.

\(\frac{4}{5}\)

Correct answer is B

\(A = {3, \sqrt{2}, 2\sqrt{3}, \sqrt{9}, \sqrt{7}}\)

n(A) = 5

Let the rational nos = R

n(R) = 2 (3, \(\sqrt{9}\))

P(R) = 2/5

1,180.

If \(K\sqrt{28}+\sqrt{63}-\sqrt{7}=0\), find K.

A.

-2

B.

-1

C.

1

D.

2

Correct answer is B

\(K\sqrt{28}+\sqrt{63}-\sqrt{7}=0\)

\(2K\sqrt{7}+3\sqrt{7}-\sqrt{7}=0\)

\(2K\sqrt{7}=-2\sqrt{7}\)

\(K=\frac{-2\sqrt{7}}{2\sqrt{7}}\)

\(K=-1\)