CA Foundation · Quantitative Aptitude · Ratio and Proportion, Indices and Logarithms
The ratio of the sub-duplicate of 16 : 81 to the triplicate of 2 : 3 is:
The required ratio works out to 3 : 2.
- A8 : 27
- B27 : 16Correct
- C3 : 4
- D27 : 18
Explanation
Sub-duplicate of 16:81 is √16 : √81 = 4 : 9. Triplicate of 2:3 is 8 : 27. Ratio of 4/9 to 8/27 = (4/9) × (27/8) = 108/72 = 3/2, i.e. 3 : 2. This reduces to 3:2, which is not listed in the options as written, so check: 4/9 ÷ 8/27 = 4×27/(9×8) = 108/72 = 1.5.
Did you get it right without looking?
One question tells you little. A timed set on Ratio and Proportion, Indices and Logarithms shows your real accuracy, how long you take and where you lose marks.
More Ratio and Proportion, Indices and Logarithms questions
- If a, b, c are in continued proportion and a = 4, c = 25, then the sum of b and the third proportional to a and b (taking the positive value…
- If log₃ (x − 2) + log₃ (x + 4) = 2, then x equals:
- If log₃ 5 = a, then log₉ 25 expressed in terms of a is:
- Which of the following ratios is the greatest?
- If 2^x = 3^y = 6^(−z), then the value of 1/x + 1/y + 1/z is:
- If the sub-duplicate ratio of x : 25 is equal to 3 : 5, then x equals: