Question 61:

• JAMB 2019

If the volume of a frustrum is given as \(V = \frac{\pi h}{3} (R^2 + Rr + r^2)\), find \(\frac{\mathrm d V}{\mathrm d R}\).

A. \(\frac{\pi h}{3} (2R + r)\)
B. \(2R + r + \frac{\pi h}{3}\)
C. \(\frac{\pi h}{3} (2R^2 + r + 2r)\)
D. \(\frac{2R^2}{3} \pi h\)

Question 62:

• JAMB 2019

Express \((0.0439 \div 3.62)\) as a fraction.

A. \(\frac{21}{100}\)
B. \(\frac{21}{1000}\)
C. \(\frac{12}{1000}\)
D. \(\frac{12}{100}\)

Question 63:

• JAMB 2019

If \(25^{1 - x} \times 5^{x + 2} \div (\frac{1}{125})^{x} = 625^{-1}\), find the value of x.

A. X = -4
B. X = 2
C. X = -2
D. X = 4

Question 64:

• JAMB 2019

A bricklayer charges #1,500 per day for himself and #500 per day for his assistant. If a two bedroom flat was built for #95,000 and the bricklayer worked 10 days more than his assistant, how much did the assistant receive?

A. N20,000
B. N28,000
C. N31,200
D. N41,000

Question 65:

• JAMB 2019

Find the equation of the locus of a point A(x, y) which is equidistant from B(0, 2) and C(2, 1)

A. 4x + 2y = 3
B. 4x - 3y = 1
C. 4x - 2y = 1
D. 4x + 2y = -1