JAMB Mathematics Past Questions & Answers - Page 159

791.

12 men complete a job in 9 days. How many men working t the same rate would be required to complete the job in 6 days?

A.

24

B.

18

C.

12

D.

9

E.

8

Correct answer is B

12 men in 9 days,

1 day in \(12 \times 9\) men

In 6 days we have \(\frac{12 \times 9}{6}\) men

= \(\frac{108}{6}\)

= 18 men

792.

Find the value of log\(_{10}\)\(\frac{1}{40}\), given that log10\(_4\) = 0.6021

A.

1.3979

B.

2.3979

C.

-1.6021

D.

2.6021

Correct answer is C

log\(_{10}\)\(\frac{1}{40}\) = log\(_{10}\)1 - (log\(_{10}\)4 + log\(_{10}\)10)

= 0 - 1.6021

= -1.6021

793.

Find the value of (4\(^{\frac{1}{2}}\))\(^6\)

A.

1

B.

2

C.

4

D.

6

E.

64

Correct answer is E

The powers will multiply when the bracket is expanded

The multiplied powers: \(\frac{1}{2}\) * 6 → 3

: 4\(^3\) = 4 * 4* 4

→ 64

794.

If x3 - 12x - 16 = 0 has x = -2 as a solution then the equaion has

A.

x = -4 as a solution also

B.

3 roots all different

C.

3 roots with two equal and the third different

D.

3 roots all equal

E.

only one root

Correct answer is B

No explanation has been provided for this answer.

795.

Solve the simultaneous linear equations: 2x + 5y = 11, 7x + 4y = 2

A.

x = -8, y = 1

B.

x = -2, y = 4

C.

x = \(\frac{-34}{27}\), y = \(\frac{73}{27}\)

D.

x = 7, y = -9

Correct answer is C

2x + 5y = 11.......(i)

7x + 4y = 2.......(ii)

(i) x 7 \(\to\) 14x + 35y = 77.........(iii)

(ii) x 2 \(\to\) 14x + 8y = 4........(iv)

(iii) - (iv)

27y = 73

y = \(\frac{73}{27}\)