JAMB Mathematics Past Questions & Answers - Page 160

797.

Which of the following values of the variable x, (a)x = 0, (b)x = -3, (c)x = 9, satisfy the inequalities 0 < \(\frac{x + 3}{x - 1}\) < 2?

A.

(a), (b), (c)

B.

(c)

C.

None of the choices

D.

All of the above

Correct answer is B

0 < \(\frac{x + 3}{x - 1}\) < 2

Put x = 0, -3 and 9

0 < \(\frac{9 + 3}{9 - 1}\) \(\leq\) 2

i.e. 0 < 1.5 \(\leq\) 2 (true)

but 0 < \(\frac{0 + 3}{0 - 1}\) \(\leq\) 2

i.e. 0 < -3 \(\leq\) 2 (not true)

-3 \(\leq\) 2

-3 is not greater than 0

798.

Make x the subject of the equation a(b + c) + \(\frac{5}{d}\) - 2 = 0

A.

c = \(\frac{2d - 5 - b}{ad}\)

B.

c = \(\frac{2d - 5 - abd}{ad}\)

C.

c = \(\frac{2d - 5 - ab}{ad}\)

D.

c = \(\frac{5 - 2d - b}{ad}\)

Correct answer is B

a(b + c) + \(\frac{5}{d}\) - 2 = 0

ab + ac + \(\frac{5}{d}\) - 2 = 0

abd + \(\frac{acd}{d}\) + 5 - 2 = ab + ac + 5 - 2d

acd = 2d - 5 - abd

c = \(\frac{2d - 5 - abd}{ad}\)

799.

PQRS is a cyclic quadrilateral with PQ as diameter of the circle. If < PQS = 15o find < QRS

A.

75o

B.

37\(\frac{1}{2}\)o

C.

127\(\frac{1}{2}\)o

D.

105o

Correct answer is D

PSO = 90o(angle in a semicircle)

SPO = 180o - (90o + 15o) = 75o

< QRS = 108o - 75o

= 105o(opposite angles in cyclic quadrilateral are supplementary)

800.

One of the following statements is wrong. Which is it?

A.

If a triangle is equiangular then it is also equilateral

B.

If a triangle is equilateral then it is also then it is also equiangular

C.

If two triangles are similar then they are also congurent

D.

The sum of the interior angles of any triangle is 180 degrees

Correct answer is C

Two similar triangles are not also congruent