JAMB Mathematics Past Questions & Answers - Page 71

351.

In how many ways can the letters LEADER be arranged?

A.

72

B.

144

C.

360

D.

720

Correct answer is C

The word LEADER has 1L 2E 1A 1D and 1R making total of 6! \(\frac{6}{1!2!1!1!1!}\) = \(\frac{6!}{2!}\)

  = \(\frac{6 \times 5 \times 4 \times 3 \times 2 \times 1}{2 \times 1}\)

  = 360

352.

Integrate the expression 6x\(^2\) - 2x + 1

A.

3x\(^3\) - 2x\(^2\) + x + c

B.

2x\(^3\) - x\(^2\) + x + c

C.

2x\(^3\) – 3x\(^2\) + c

D.

x\(^3\) + x\(^2\) – x + c

Correct answer is B

6x\(^2\) - 2x + 1

\(\frac{6x^{2+1}}{2+1} - \frac{2x^{1+1}}{1+1}+ 1x = \frac{6x^3}{3} - \frac{2x^2}{2} + x\)

\(2x^3 - x^2 + x + c\)

354.

A man's initial salary is N540.00 a month and increases after each period of six months by N36.00. Find his salary in the eight month of the third year.

A.

N828.00

B.

N756.00

C.

N720.00

D.

N684.00

Correct answer is C

Since the salary increases by #36 after every 6 months

: 2 years and 8 months imply an increase of five times only:

36 * 5 →  #180

 His salary then = initial salary + increment

  = 540 + 180

  = #720

  Answer is C

355.

Find the equation of the line through (5,7) parallel to the line 7x + 5y = 12 

A.

5x + 7y = 20

B.

x + 5y = 70

C.

xy = 7

D.

15x + 17y = 90

Correct answer is B

No explanation has been provided for this answer.