Year : 
2012
Title : 
Mathematics (Core)
Exam : 
JAMB Exam

Paper 1 | Objectives

31 - 40 of 48 Questions

# Question Ans
31.

Evaluate \(\int^{\frac{\pi}{4}}_0sec^2 \theta d \theta\)

A. 1

B. 2

C. 3

D. 4

Detailed Solution

\(\int^{\frac{\pi}{4}}_0sec^2 \theta d \theta\)
= \([\tan \theta]_{0} ^{\frac{\pi}{4}}\)
= \(\tan \frac{\pi}{4} - \tan 0\)
= \(1 - 0\)
= 1.
There is an explanation video available below.
32.

The mean of seven numbers is 96. If an eighth number is added, the mean becomes 112. Find the eighth number.

A. 126

B. 180

C. 216

D. 224

Detailed Solution

\(\frac{x}{7} = \frac{96}{1}\) ==> \(\frac{672 + x}{8} = 112\)

Therefore x = 224
33.

Find the median of 2,3,7,3,4,5,8,9,9,4,5,3,4,2,4 and 5

A. 9

B. 8

C. 7

D. 4

Detailed Solution

There is an explanation video available below.
34.

Find the range of 4,9,6,3,2,8,10 and 11

A. 11

B. 9

C. 8

D. 4

Detailed Solution

There is an explanation video available below.
35.

Find the standard deviation of 2,3,8,10 and 12

A. 3.9

B. 4.9

C. 5.9

D. 6.9

Detailed Solution

There is an explanation video available below.
36.

Evaluate n+1Cn-2 If n =15

A. 3630

B. 3360

C. 1120

D. 560

Detailed Solution

There is an explanation video available below.
37.

In how many ways can the letters of the word TOTALITY be arranged?

A. 6720

B. 6270

C. 6207

D. 6027

Detailed Solution

There is an explanation video available below.
38.

The probability that a student passes a physics test is \(\frac{2}{3}\). If he takes three physics tests, what is the probability that he passes two of the tests?

A. \(\frac{2}{27}\)

B. \(\frac{3}{27}\)

C. \(\frac{4}{27}\)

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

Detailed Solution

There is an explanation video available below.
39.

The probabilities that a man and his wife live for 80 years are \(\frac{2}{3}\) and \(\frac{3}{5}\) respectively. Find the probability that at least one of them will live up to 80 years

A. \(\frac{2}{15}\)

B. \(\frac{3}{15}\)

C. \(\frac{7}{15}\)

D. \(\frac{13}{15}\)

Detailed Solution

Man lives = \(\frac{2}{3}\) not live = \(\frac{1}{3}\)

Wife lives = \(\frac{3}{5}\) not live = \(\frac{2}{5}\)
P(at least one lives to 80 years) = P(man lives to 80 not woman) + P(woman lives to 80 and not man) + P(both live to 80)
\(P = (\frac{2}{3} \times \frac{2}{5}) + (\frac{2}{5} \times \frac{1}{3}) + (\frac{2}{3} \times \frac{3}{5})\)

= \(\frac{4}{15} + \frac{3}{15} + \frac{6}{15}\)

= \(\frac{13}{15}\)
There is an explanation video available below.
40.

The shaded region above is represented by
the equation

A. y ≤ 4x + 2

B. y ≥ 4x + 2

C. y ≤ -4x + 4

D. y ≤ 4x + 4

Detailed Solution

Equation of the line
\(\frac{y - 4}{x - 0} = \frac{0 - 4}{1 - 0}\)
\(\frac{y - 4}{x} = \frac{-4}{1}\)
\(\therefore -4x = y - 4\)
\(y = -4x + 4\)
\(\therefore \text{The shaded portion = } y \leq -4x + 4\)
There is an explanation video available below.
31.

Evaluate \(\int^{\frac{\pi}{4}}_0sec^2 \theta d \theta\)

A. 1

B. 2

C. 3

D. 4

Detailed Solution

\(\int^{\frac{\pi}{4}}_0sec^2 \theta d \theta\)
= \([\tan \theta]_{0} ^{\frac{\pi}{4}}\)
= \(\tan \frac{\pi}{4} - \tan 0\)
= \(1 - 0\)
= 1.
There is an explanation video available below.
32.

The mean of seven numbers is 96. If an eighth number is added, the mean becomes 112. Find the eighth number.

A. 126

B. 180

C. 216

D. 224

Detailed Solution

\(\frac{x}{7} = \frac{96}{1}\) ==> \(\frac{672 + x}{8} = 112\)

Therefore x = 224
33.

Find the median of 2,3,7,3,4,5,8,9,9,4,5,3,4,2,4 and 5

A. 9

B. 8

C. 7

D. 4

Detailed Solution

There is an explanation video available below.
34.

Find the range of 4,9,6,3,2,8,10 and 11

A. 11

B. 9

C. 8

D. 4

Detailed Solution

There is an explanation video available below.
35.

Find the standard deviation of 2,3,8,10 and 12

A. 3.9

B. 4.9

C. 5.9

D. 6.9

Detailed Solution

There is an explanation video available below.
36.

Evaluate n+1Cn-2 If n =15

A. 3630

B. 3360

C. 1120

D. 560

Detailed Solution

There is an explanation video available below.
37.

In how many ways can the letters of the word TOTALITY be arranged?

A. 6720

B. 6270

C. 6207

D. 6027

Detailed Solution

There is an explanation video available below.
38.

The probability that a student passes a physics test is \(\frac{2}{3}\). If he takes three physics tests, what is the probability that he passes two of the tests?

A. \(\frac{2}{27}\)

B. \(\frac{3}{27}\)

C. \(\frac{4}{27}\)

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

Detailed Solution

There is an explanation video available below.
39.

The probabilities that a man and his wife live for 80 years are \(\frac{2}{3}\) and \(\frac{3}{5}\) respectively. Find the probability that at least one of them will live up to 80 years

A. \(\frac{2}{15}\)

B. \(\frac{3}{15}\)

C. \(\frac{7}{15}\)

D. \(\frac{13}{15}\)

Detailed Solution

Man lives = \(\frac{2}{3}\) not live = \(\frac{1}{3}\)

Wife lives = \(\frac{3}{5}\) not live = \(\frac{2}{5}\)
P(at least one lives to 80 years) = P(man lives to 80 not woman) + P(woman lives to 80 and not man) + P(both live to 80)
\(P = (\frac{2}{3} \times \frac{2}{5}) + (\frac{2}{5} \times \frac{1}{3}) + (\frac{2}{3} \times \frac{3}{5})\)

= \(\frac{4}{15} + \frac{3}{15} + \frac{6}{15}\)

= \(\frac{13}{15}\)
There is an explanation video available below.
40.

The shaded region above is represented by
the equation

A. y ≤ 4x + 2

B. y ≥ 4x + 2

C. y ≤ -4x + 4

D. y ≤ 4x + 4

Detailed Solution

Equation of the line
\(\frac{y - 4}{x - 0} = \frac{0 - 4}{1 - 0}\)
\(\frac{y - 4}{x} = \frac{-4}{1}\)
\(\therefore -4x = y - 4\)
\(y = -4x + 4\)
\(\therefore \text{The shaded portion = } y \leq -4x + 4\)
There is an explanation video available below.