A person ordered 5 pairs of black socks and some pairs of brown socks. The price of a black pair was thrice that of a brown pair. While preparing the bill, the bill clerk interchanged the number of black and brown pairs by mistake which increased the bill by 100%. What was the number of pairs of brown socks in the original order?
A
10
B
15
C
20
D
25
Correct Answer: Option D
Explanation
Let's solve this simply. The actual price of socks doesn't matter, just their relat