Jamb Mathematics Past Questions and Answers

Question 486:

• JAMB 1978

Father reduced the quantity of food bought for the family by 10% when he found that the cost of living had increased 15%. Thus the fractional increase in the family food bill is now

A. \(\frac{1}{12}\)
B. \(\frac{6}{35}\)
C. \(\frac{19}{300}\)
D. \(\frac{7}{200}\)
E. \(\frac{5}{100}\)

Question 487:

• JAMB 1978

Given that \(a*b = ab + a + b\) and that \(a ♦ b = a + b = 1\). Find an expression (not involving * or ♦) for (a*b) ♦ (a*c) if a, b, c, are real numbers and the operations on the right are ordinary addition and multiplication of numbers

A. Ac + ab + bc + b + c + 1
B. Ac + ab + a + c + 2
C. Ab + ac + a + b + 1
D. Ac + bc + ab + b + c + 2
E. Ab + ac + 2a + b + c + 1

Question 488:

• JAMB 1978

If a circular paper disc is trimmed in such a way that its circumference is reduced in the ratio 2:5, In what ratio is the surface area reduced?

A. 8 : 125
B. 2 : 5
C. 8 : 25
D. 4 : 25
E. 4 : 10

Question 489:

• JAMB 1978

If the four interior angles of a quadrilateral are (p + 10)o, (p - 30)o, (2p - 450o, and (p + 15)o, then p is

A. 125^o
B. 82^o
C. 135^o
D. 105^o
E. 60^o

Question 490:

• JAMB 1978

Simplify \(\frac{a - b}{a + b}\) - \(\frac{a + b}{a - b}\)

A. \(\frac{4ab}{a - b}\)
B. \(\frac{-4ab}{a^2 - b^2}\)
C. \(\frac{-4ab}{a^{-2} - b}\)
D. \(\frac{4ab}{a^{-2} - b^{-2}}\)