JAMB Mathematics Past Questions & Answers - Page 322

1,606.

Find the remainder when X3 - 2X2 + 3X - 3 is divided by X2 + 1

A.

2X - 1

B.

X + 3

C.

2X + 1

D.

X - 3

Correct answer is A

X2 + 1 \(\frac{X - 2}{\sqrt{X^3 - 2X^2 + 3n - 3}}\)

= \(\frac {- 6X^3 + n}{-2X^2 + 2X - 3}\)

= \(\frac{(-2X^2 - 2)}{2X - 1}\)

Remainder is 2X - 1

1,607.

Make R the subject of the formula if T = \(\frac {KR^2 + M}{3}\)

A.

\(\sqrt\frac{3T - K}{M}\)

B.

\(\sqrt\frac{3T - M}{K}\)

C.

\(\sqrt\frac{3T + K}{M}\)

D.

\(\sqrt\frac{3T - K}{M}\)

Correct answer is B

T = \(\frac{KR^2 + M}{3}\)

3T = KR2 + M

KR2 = 3T - M

R2 = \(\frac{3T - M}{K}\)

R = \(\sqrt\frac{3T - M}{K}\)

1,608.

Raial has 7 different posters to be hanged in her bedroom, living room and kitchen. Assuming she has plans to place at least a poster in each of the 3 rooms, how many choices does she have?

A.

49

B.

170

C.

21

D.

210

Correct answer is D

The first poster has 7 ways to be arranges, the second poster can be arranged in 6 ways and the third poster in 5 ways.

= 7 x 6 x 5

= 210 ways

or \(\frac{7}{P_3}\) = \(\frac{7!}{(7 - 3)!}\) = \(\frac{7!}{4!}\)

= \(\frac{7 \times 6 \times 5 \times 4!}{4!}\)

= 210 ways

1,609.

Simplify (\(\sqrt2 + \frac{1}{\sqrt3})(\sqrt2 - \frac{1}{\sqrt3}\))

A.

\(\frac{7}{3}\)

B.

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

C.

\(\frac{5}{2}\)

D.

\(\frac{3}{2}\)

Correct answer is B

(\(\sqrt2 + \frac{1}{\sqrt3})(\sqrt2 - \frac{1}{\sqrt3}\))

\(\sqrt4 - \frac {\sqrt2}{\sqrt3} + \frac {\sqrt2}{\sqrt3} - \frac {1}{\sqrt9}\)

= 2 - \(\frac {1}{3}\)

= \(\frac {16 - 1}{3}\)

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

1,610.

Rationalize \(\frac{2 - \sqrt5}{3 - \sqrt5}\)

A.

\(\frac{1 - \sqrt5}{2}\)

B.

\(\frac{1 - \sqrt5}{4}\)

C.

\(\frac{ \sqrt5 - 1}{2}\)

D.

\(\frac{1 + \sqrt5}{4}\)

Correct answer is B

\(\frac{2 - \sqrt5}{3 - \sqrt5}\) x \(\frac{3 + \sqrt5}{3 + \sqrt5}\)

\(\frac{(2 - \sqrt5)(3 + \sqrt5)}{(3 - \sqrt5)(3 + \sqrt5)}\) = \(\frac{6 +2\sqrt5 - 3\sqrt5 - \sqrt25}{9 + 3\sqrt5 - 3\sqrt5 - \sqrt25}\)

= \(\frac{6 - \sqrt5 - 5}{9 - 5}\)

= \(\frac{1 - \sqrt5}{4}\)