If 30% of A = 0.25 of B = \(\frac{1}{5}\) of C, then find A: B: C.
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 10:12:15
When three quantities are equal, set each of them equal to one common value k; then A, B and C can each be written in terms of k and compared directly.
30% of A is k, so \(0.30A=k\) and \(\displaystyle A=\frac{10k}{3}\)
0.25 of B is k, so \(B=4k\)
One-fifth of C is k, so \(C=5k\)
The ratio is \(\displaystyle A:B:C=\frac{10}{3}:4:5\); multiplying each term by 3 to clear the fraction gives 10 : 12 : 15