The weights of two persons A and B are in the ratio of 3 : 5. A's weight increases by 20% and the total weight of A and B together becomes 80kg, with an increase of 25%. By what percent did the weight of B increase ?
A. 20%
B. 25%
C. 28%
D. 30%
Answer: Option C
Solution(By Examveda Team)
Let the initial total weight of A and B be x kg.Then,
$$\eqalign{ & = 125\% {\text{ of }}x = 80 \cr & \Rightarrow x = 80 \times \frac{{100}}{{125}} = 64{\text{kg}} \cr & {\text{A's initial weight}} \cr & = \left( {64 \times \frac{3}{8}} \right){\text{kg}} \cr & = 24{\text{kg}}{\text{}} \cr & {\text{B's initial weight}} \cr & = \left( {64 \times \frac{5}{8}} \right){\text{kg}} \cr & = 40{\text{kg}} \cr & {\text{A's new weight}} \cr & = 120\% {\text{ of }}24{\text{kg}} \cr & = 28.8{\text{kg}}{\text{}} \cr & {\text{B's new weight}} \cr & = \left( {80 - 28.8} \right){\text{kg}} \cr & = 51.2{\text{kg}} \cr & {\text{Increase in B's weight}} \cr & = \left( {51.2 - 40} \right){\text{kg}} \cr & = 11.2{\text{kg}} \cr & \therefore {\text{Increase }}\% \cr & = \left( {\frac{{11.2}}{{40}} \times 100} \right)\% \cr & = 28\% \cr} $$
Related Questions on Ratio
If a : b : c = 3 : 4 : 7, then the ratio (a + b + c) : c is equal to
A. 2 : 1
B. 14 : 3
C. 7 : 2
D. 1 : 2
If $$\frac{2}{3}$$ of A=75% of B = 0.6 of C, then A : B : C is
A. 2 : 3 : 3
B. 3 : 4 : 5
C. 4 : 5 : 6
D. 9 : 8 : 10
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