JAMB Mathematics Past Questions & Answers - Page 81

401.

The pie chart shows the allocation of money to each sector in a farm. The total amount allocated to the farm is ₦ 80 000. Find the amount allocated to fertilizer

A.

₦ 35, 000

B.

₦ 40,000

C.

₦ 25,000

D.

₦ 20,000

Correct answer is D

Total angle at a point = 3600

∴ To get the angle occupied by fertilizer we have,

40 + 50 + 80 + 70 + 30 + fertilizer(x) = 360

270 + x = 360

x = 360 - 270

x = 90

Total amount allocated to the farm
= ₦ 80,000

∴Amount allocated to the fertilizer

= \(\frac{\text{fertilizer (angle) × Total amount}}{\text{total angle}}\)

= \(\frac{90}{360}\) × 80,000

= ₦20,000

402.

Find the principal which amounts to ₦ 5,500 at a simple interest in 5 years at 2% per annum

A.

₦ 4,900

B.

₦ 5,000

C.

₦ 4,700

D.

₦ 4,000

Correct answer is B

Principal = P, Simple Interest = I, Amount = A

Amount = Principal + Simple Interest

I = \(\frac{PRT}{100}\)

R = rate, T = time

I = \(\frac{P \times 5 \times 2}{100}\)

I = \(\frac{10P}{100}\)

I = \(\frac{P}{10}\)

Amount A = P + I

5500 = P + \(\frac{P}{10}\)

Multiply through by 100

5500 = 10P + P

5500 = 11P

p = \(\frac{5500}{11}\)

p = ₦5000

403.

If a rod 10cm in length was measured as 10.5cm, calculate the percentage error

A.

5%

B.

5%

C.

8%

D.

7%

Correct answer is A

Actual measurement = 10cm

approximated value of measurement = 10.5cm

% error = \(\frac{\text{Actual measurement − Approximated}}{\text{Actual measure}}\) × 100

= \(\frac{10 − 10.5}{10}\) × 100

= \(\frac{-0.5}{10}\) × 100

ignore -sign i.e take absolute value

= \(\frac{0.5}{10}\) × 100

= 5 %

404.

Evaluate \(\frac{0.00000231}{0.007}\) and leave the answer in standard form

A.

3.3 x 10-4

B.

3.3 x 10-3

C.

3.3 x 10-5

D.

3.3 x 10-8

Correct answer is A

\(\frac{0.00000231}{0.007}\) to standard form

= \(\frac{231 \times 10^{-8}}{7 \times 10^{-3}}\)

= 33 × 10\(^{-8 − (−3)}\)

= 33 × 10\(^{− 8 + 3}\)

= 33 × 10-5

= 3.3 x 10^-4

405.

Find the number of ways that the letters of the word EXCELLENCE be arranged

A.

\(\frac{10!}{2!2!2!}\)

B.

\(\frac{10!}{4!2!}\)

C.

\(\frac{10!}{4!2!2!}\)

D.

\(\frac{10!}{2!2!}\)

Correct answer is C

EXCELLENCE

It is a ten letter word = 10!

Since we have repeating letters, we have to divide to remove the duplicates accordingly. There are 4 Es, 2 Cs, 2 Ls

∴ there are
\(\frac{10!}{4!2!2!}\) ways to arrange