JAMB Mathematics Past Questions & Answers - Page 103

511.

Simplify \(6\frac{1}{12} − 2 ¾ + 1 ½ \)

A.

\( 3 \frac{5}{6}\)

B.

\( 4 \frac{5}{6}\)

C.

\( 2 \frac{1}{6}\)

D.

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

Correct answer is B

6½ − 2¾ + 1½

73/12 − 11/4 + 3/2

[(73 − 33 + 18) ÷ (12)]

58/12

29/6

\( 4\frac{5}{6}\)

512.

A man bought a car for N800 and sold it for N520. Find his loss per cent

A.

15%

B.

25%

C.

35%

D.

10%

Correct answer is C

Percentage Loss = (actual loss ) ÷ (Cost price) × 100 Actual loss = Cost Price − Selling Price (sold price) = N800 − N520 = N280 Percentage loss = (280 ÷ 800) × 100 = 35% ∴ His loss percent = 35%

513.

If (159.75)10 = (x)6. Find x

A.

x6 = 123.346

B.

x6 = 424.56

C.

x6 = 122.436

D.

x6 = 124.456

Correct answer is B

(159.75)10 = (y)6

\( \begin{array}{c|c}
6 & 159 \\
\hline
6 & 26 \text{ rem 3} \\
6 & 4 \text{ rem 2} \\
& 0 \text{ rem 4} \\
\end{array}\uparrow \)

15910 = 4236

Then Convert 0.75 to base 6

0.75 x 6 =4.5 i.e 4.5 - 3.00 = 1.5
0.5 x 6 = 3.00 423 + 1.5 =424.5

159.75 = (424.5)6

(159)10 = (424.5)6

514.

The probability of an event A is 1/5. The probability of B is 1/3 . The probability both A and B is 1/15. What is the probability of either event A or B or both

A.

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

B.

\( \frac{3}{4} \)

C.

\( \frac{9}{15} \)

D.

\( \frac{1}{15} \)

Correct answer is C

No explanation has been provided for this answer.

515.

The volume of a cylinder whose height is 4cm and whose radius 5cm is equal to (π = 3.14)

A.

3.13cm2

B.

145cm2

C.

314cm2

D.

214cm2

Correct answer is C

“Explanation

V = πr2h

V = ?, h = 4cm, r = 5cm

V = 3.14(5)2 (4)

V = 3.14(25)(4)

V = 3.14 × 1200

= 314cm2