JAMB Mathematics Past Questions & Answers - Page 170

846.

A man and his wife went to buy an article costing N400. The woman had 10% of the cost and the man 40% of the remainder. How much did they have altogether?

A.

N216

B.

N200

C.

N184

D.

N144

E.

N100

Correct answer is C

10% of 400 = N40, Remainder = N360 40% of 360 = N144 Altogether they 144 + 40 = N184

847.

P and Q are fixed points and X is a variable point which moves so that angle PXQ = 45o. What is the locus of x?

A.

A pair of straight lines parallel to PQ

B.

The perpendicular bisector of PQ

C.

An arc of a circle passing through P and Q

D.

A circle with diameter PQ

E.

The bisector of angle PXQ

Correct answer is B

No explanation has been provided for this answer.

848.

The ratio of the areas of similar triangles is necessarily equal to

A.

the ratio of the corresponding sides

B.

the ratio of the squares of corresponding sides

C.

the ratio of the corresponding heights of the triangles

D.

half the ratio of the corresponding heights of the triangles

E.

the ratio of the corresponding bases to the heights of the triangles

Correct answer is B

The ratio of the areas of two similar triangles is equal to the square of ratio of their corresponding sides.

849.

A solid cylinder of radius 3cm has a total surface area of 36\(\pi\)cm2. Find its height

A.

2cm

B.

3cm

C.

4cm

D.

5cm

E.

6cm

Correct answer is B

Area 2\(\pi\)r2 + 2 \(\pi\)r(r + h)

= 2\(\pi\)r(r + h)

36\(\pi\) = 6\(\pi\)(r + h)

36\(\pi\) = 6\(\pi\)(3 + h)

36\(\pi\) = 18\(\pi\) + 6\(\pi\)h

36\(\pi\) - 18\(\pi\) = 6\(\pi\)h

Divide both side by 6\(\pi\)

h = 3cm

850.

Find the roots of the equation 10x2 - 13x - 3 = 0

A.

x = \(\frac{3}{5}\) or -\(\frac{1}{2}\)

B.

x = \(\frac{3}{10}\) or -1

C.

x = \(\frac{3}{10}\) or 1

D.

x = \(\frac{1}{5}\) or \(\frac{-3}{2}\)

E.

x = -\(\frac{1}{5}\) or \(\frac{3}{2}\)

Correct answer is E

10x2 - 13x - 3 = 0 = 10x2 - 15x + 2x - 3 = 0

5x(2x - 3) + 2x - 3 = 0

= (5x + 1)(2x - 3) = 0

5x + 1 = 0 or 2x - 3 = 0

x = -\(\frac{1}{5}\) or \(\frac{3}{2}\)