JAMB Mathematics Past Questions & Answers - Page 90

446.

If N = \(\frac{p}{2}\)(\(\frac{T_1 - T_2}{T_1}\)). Find P when N = 12, T1 = 27 and T2 = 24.

A.

48

B.

108

C.

54

D.

216

Correct answer is D

N = \(\frac{p}{2}\)(\(\frac{T_1 - T_2}{T_1}\))
12 = \(\frac{p}{2}\)(\(\frac{27 - 24}{27}\))
24 = P(\(frac{3}{27}\)
P = 24 x 9 = 216

447.

Evaluate \(\int\)(sinx - 5x2)dx

A.

-cosx - 10x + k

B.

cosx - \(\frac{5x^3}{3}\) + k

C.

-cosx - \(\frac{5x^3}{3}\) + k

D.

cosx - 10x + k

Correct answer is C

\(\int\)(sin x - 5x^2) = -cosx - \(\frac{5x^3}{3}\) + k

448.

Find \(\frac{dy}{dx}\). If y = 3x3 + 2x2 + 3x + 1

A.

9x2 + 4x + 3

B.

9x2 - 4x - 3

C.

9x2 + 4x - 3

D.

9x2 - 4x + 3

Correct answer is A

y = 3x3 + 2x2 + 3x + 1
\(\frac{dy}{dx}\) = 9x2 + 4x + 3

449.

If a car travels 120km on 45 litres of petrol, how much petrol is needed for a journey of 600km?

A.

720 litres

B.

160 litres

C.

225 litres

D.

960 litres

Correct answer is C

120km \(\to\) 45litres
1km \(\to\) \(\frac{45}{120}\)litres
600km \(\to\) \(\frac{45}{120}\) x 600 = 225litres

450.

Simplify 1 - (\(\frac{1}{7}\) x 3 \(\frac{1}{2}\)) \(\div\) \(\frac{3}{4}\)

A.

2

B.

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

C.

1

D.

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

Correct answer is B

1 - (\(\frac{1}{7}\) x 3 \(\frac{1}{2}\)) \(\div\) \(\frac{3}{4}\)

1 - (\(\frac{1}{7}\) x \(\frac{7}{2}\)) x \(\frac{4}{3}\)

1 - \(\frac{1}{2}\) x \(\frac{4}{3}\)

1 - \(\frac{2}{3}\) = \(\frac{1}{3}\)