Jamb Mathematics 1981 Past Questions and Answers

Question 31:

• JAMB 1981

The difference between the length and width of a rectangle is 6cm and the area is 135cm2. What is the length?

A. 25cm
B. 18cm
C. 15cm
D. 24cm
E. 27cm

Question 32:

• JAMB 1981

The area of a circular plate is one-sixteenth the surface area of a ball of a ball, If the area of the plate is given as P cm², then the radius of the ball is

A. \(\frac{2P}{\pi}\)
B. \(\frac{P}{\sqrt{\pi}}\)
C. \(\frac{P}{\sqrt{2\pi}}\)
D. 2\(\frac{P}{\pi}\)

Question 33:

• JAMB 1981

Show that \(\frac{\sin 2x}{1 + \cos x}\) + \(\frac{sin2 x}{1 - cos x}\) is

A. Sin x
B. Cos²x
C. 2
D. 3

Question 34:

• JAMB 1981

The first term of an Arithmetic progression is 3 and the fifth term is 9. Find the number of terms in the progression if the sum is 81

A. 12
B. 27
C. 9
D. 4
E. 36

Question 35:

• JAMB 1981

Simplify T = \(\frac{4R_2}{R_1^{-1} + R_2^{-1} + 4R_3^{-1}}\)

A. \(\frac{4R_1 \times R_2 R_3}{R_2R_3 + R_1R_3 + 4R_1 R_2}\)
B. \(\frac{R_1 R_2 R_3}{R_2R_3 + R_1R_2 + 4R_1 R_2}\)
C. \(\frac{16R_1 R_2 R_3}{R_2R_3 + R_1R_2 + R_1 R_2}\)
D. \(\frac{4R_1 R_2 R_3}{4R_2R_3 + R_1R_2 + 4R_1 R_2}\)