JAMB Mathematics Past Questions & Answers - Page 67

331.

From a point P, Q is 5km due West and R is12km due South of Q. Find the distance between P and R.

A.

5km

B.

12km

C.

13km

D.

17km

Correct answer is C

Using Pythagoras theorem

  PR\(^2\) = 5\(^2\) + 12\(^2\)

  25 + 144 = 169

  PR = √(169)= 13km

 

332.

Out of 7 consonants and 4 vowels, how many words of 3 consonants and 2 vowels can be formed?

A.

210

B.

1050

C.

21400

D.

25200

Correct answer is A

To form words having 3 consonants and 2 vowels out of 7 consonants and 4 vowels, the number of such words is 7/3C x 4/2C = 35 x 6

  = 210

333.

Tossing a coin and rolling a die are two separate events. What is the probability of obtaining a tail on the coin and an even number on the die?

A.

\(\frac{1}{16}\)

B.

\(\frac{1}{6}\)

C.

\(\frac{1}{4}\)

D.

\(\frac{3}{8}\)

Correct answer is C

P( tail on a coin) = \(\frac{1}{2}\)

  Even numbers on a care 2, 4 and 6

  P( even number on a die) = \(\frac{3}{6}\) = \(\frac{1}{2}\)

  P( tail on a coin and even number on a die) = \(\frac{1}{2}\) x \(\frac{1}{2}\) = \(\frac{1}{4}\)

334.

Evaluate ∫\(^2_1\) \(\frac{5}{x}\) dx

A.

1.47

B.

2.67

C.

3.23

D.

3.47

Correct answer is D

∫\(\frac{5}{x}\) dx = 5 ∫\(\frac{1}{x}\) = 5Inx

  Since the integral of \(\frac{1}{x}\) is Inx

  ∫\(^2\) \(_1\)∫ \(\frac{5}{x}\) dx = 5

  dx = 5 (In<2 – InIn1)

  = 3.4657

  = 3.47

335.

Calculate 243\(_{six}\) – 243\(_{five}\) expressing your answer in base 10

A.

0

B.

1

C.

26

D.

46

Correct answer is C

Since they are of different base, convert to base 10

  243\(_{six}\) = (2 x 62) + (4 x 61) + (3 x 60)

  = 72 + 24 + 3 = 99 base 10

  243\(_{six}\) = 2 x 52 + 4 x 51 +3 x 50

  50 + 20 + 3 = 73 base 10

  Subtracting them, 99 - 73

  = 26