The profits of QRS company rose 40% from March to April, then dropped 20% from April to May, then rose 50% from May to June. What was the percent increase for the whole quarter, from March to June?  Choose the correct choice from the following options:
A) 15 %
B) 32 %
C) 40 %
D) 68 %
E) 80 %

Rationale: "assume 100 in march , then 140 in april as 40 % increase , then 112 in may as 20 % decrease from april , and then 168 in june which is 150 % of 112 . so overall increase is from 100 to 168 is 68 % answer d"
Answer: D