JAMB Mathematics Past Questions & Answers - Page 150

746.

Two triangles have the same areas if

A.

Two sides in one triangle are equal to two sides in the other

B.

Three sides in one triangle are equal to three sides in the other

C.

Two angles in the triangle are equal to two angles in the other

D.

Three angles in one triangle are equal to three angles in the other

E.

One side and the opposite angle in one triangle are equal to one side and the opposite angle in the other

Correct answer is B

Two triangles have the same area if three sides in one triangle equal to three in the other.

747.

The quantity (x + y) is a factor of

A.

x2 + y2

B.

x3 - y3

C.

2x2 - 3xy + y2 - x + 1

D.

2x3 + 2x2y - xy + 3x - y2 + 3y

E.

x5 - y5

Correct answer is D

(x + y) is a factor 2x3 + 2x2y - xy + 3x - y^2

748.

A solid sphere of radius 3cm, a solid right cone of radius 3cm and height 12cm and a solid right circular cycular of radius 3cm and height 4cm.Which of the following statements is true?

A.

The volume of the sphere is greater than the volume of the cone

B.

The volume of the cone is less than the volume of the cylinder

C.

The total surface area of the cone is greater than that of the sphere

D.

The total surface area of the cylinder is less than that of the sphere

E.

The total sufeac area of the cone is equal to that of the cylinder

Correct answer is C

No explanation has been provided for this answer.

749.

The set of value of x and y which satisfies the equations x2 - y - 1 = 0 and y - 2x + 2 = 0 is

A.

1, 0

B.

1, 1

C.

2, 2

D.

0, 2

E.

1, 2

Correct answer is A

x2 - y - 1 = 0.......(i)

y - 2x + 2 = 0......(ii)

By re-arranging eqn. (ii)

y = 2x - 2........(iii)

Subst. eqn. (iii) in eqn (i)

x2 - (2x - 2) - 1 = 0

x2 - 2x + 1 = 0

= (x - 1) = 0

When x - 1 = 0

x = 1

Sub. for x = 1 in eqn. (iii)

y = 2 - 2 = 0

x = 1, y = 0

750.

A hollow right prism of equilateral triangular base of side 4cm is filled with water up to a certain height. If a sphere of radius \(\frac{1}{2}\)cm is immersed in the water, then the rise of water is

A.

1cm

B.

\(\sqrt{\frac{3\pi}{24}}\)

C.

\(\frac{\pi}{24\sqrt{3}}\)

D.

24\(\sqrt{3}\)

Correct answer is C

The rise of water is equivalent to the volume of the sphere of radius \(\frac{1}{2}\)cm immersed x \(\frac{1}{\text{No. of sides sq. root 3}}\)

Vol. of sphere of radius = 4\(\pi\) x \(\frac{1}{8}\) x \(\frac{1}{3}\) - (\(\frac{1}{2}\))3

= \(\frac{1}{8}\)

= \(\frac{\pi}{6}\) x \(\frac{1}{4\sqrt{3}}\)

= \(\frac{\pi}{24\sqrt{3}}\)