Skip to content

CMA Foundation · Fundamentals of Business Mathematics and Statistics · Indices and Logarithms

The value of (27)^(2/3) × (16)^(-1/4) is:

The value is 9/2. Since 27^(2/3) = 3^2 = 9 and 16^(-1/4) = 1/2, because the negative power gives a reciprocal of the fourth root of 16, the product is 9 × 1/2 = 9/2. Ignoring the negative sign would wrongly give 18.

  1. A9/2Correct
  2. B3/2
  3. C18
  4. D9/4

Explanation

27^(2/3) = (3^3)^(2/3) = 3^2 = 9. 16^(-1/4) = 1/(2^4)^(1/4) = 1/2. The product is 9 × 1/2 = 9/2. Option 18 results from ignoring the negative sign and using 16^(1/4)=2.

Did you get it right without looking?

One question tells you little. A timed set on Indices and Logarithms shows your real accuracy, how long you take and where you lose marks.

More Indices and Logarithms questions