JAMB Mathematics Past Questions & Answers - Page 204

1,017.

Two points X and Y both on latitude 60oS have longitude147oE and 153oW respectively. Find to the nearest kilometer the distance between X and Y measured along the parallel of latitude(Take 2\(\pi\)R = 4 x 104km, where R is the radius of the earth)

A.

16667km

B.

28850km

C.

8333km

D.

2233km

Correct answer is A

Length of an area = \(\frac{\theta}{360}\) x 2\(\pi\)r

Longitude difference = 147 + 153 = 30NoN

distance between xy = \(\frac{\theta}{360}\) x 2\(\pi\)R cos60o

= \(\frac{300}{360}\) x 4 x 104 x \(\frac{1}{2}\)

= 1.667 x 104km(1667 km)

1,018.

A bag contains 4 white balls and 6 red balls. Two balls are taken from the bag without replacement. What is the probability that they are both red?

A.

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

B.

\(\frac{2}{15}\)

C.

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

D.

\(\frac{1}{3}\)

Correct answer is D

P(R1) = \(\frac{6}{10}\)

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

P(R1 n R11) = P(both red)

\(\frac{3}{5}\) x \(\frac{5}{9}\)

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

1,019.

PRSQ is a trapezium of area 14cm2 in which PQ||RS. If PQ = 4cm and SR = 3cm, Find the area of SQR in cm2

A.

7.0

B.

6.0

C.

5.2

D.

5.0

Correct answer is B

Area of trapezium = 14cm2

Area of trapezium = \(\frac{1}{2}\)(a + b)h

14 = \(\frac{1}{2}\)(4 + 3)h

14 = \(\frac{7}{2}\)h

h = \(\frac{14 \times 2}{7}\)

= 4

Area of SQR = \(\frac{1}{2}\)(3 x 4)

= \(\frac{12}{2}\)

= 6.0

1,020.

A solid sphere of radius 4cm has a mass of 64kg. What will be the mass of a shell of the same metal whose internal and external radii are 2cm and 3cm respectively?

A.

5kg

B.

16kg

C.

19kg

D.

6kg

Correct answer is A

\(\frac{1\sqrt{3}}{(\frac{1}{2})^2}\)

= \(\frac{4}{\sqrt{3}}\)

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

= \(\frac{4\sqrt{3}}{\sqrt{3}}\)

m = 64kg, V = \(\frac{4\pi r^3}{3}\)

= \(\frac{4\pi(4)^3}{3}\)

= \(\frac{256\pi}{3}\) x 10-6m3

density(P) = \(\frac{\text{Mass}}{\text{Volume}}\)

= \(\frac{64}{\frac{256\pi}{3 \times 10^{-6}}}\)

= \(\frac{64 \times 3 \times 10^{-6}}{256}\)

= \(\frac{3}{4 \times 10^{-6}}\)

m = PV = \(\frac{3}{4 \pi \times 10^{-6}}\) x \(\frac{4}{3}\) \(\pi\)[32 - 22] x 10-6

\(\frac{3}{4 \times 10^{-6}}\) x \(\frac{4}{3}\) x 5 x 10-6

= 5kg