If Teena is driving at 55 miles per hour and is currently 7.5 miles behind Roe, who is driving at 40 miles per hour in the same direction then in how many minutes will Teena be 15 miles ahead of Roe?	Options:
A) 15
B) 60
C) 75
D) 90
E) 105

Rationale: "this type of questions should be solved without any complex calculations as these questions become imperative in gaining that extra 30 - 40 seconds for a difficult one . teena covers 55 miles in 60 mins . roe covers 40 miles in 60 mins so teena gains 15 miles every 60 mins teena need to cover 7.5 + 15 miles . teena can cover 7.5 miles in 30 mins teena will cover 15 miles in 60 mins so answer 30 + 60 = 90 mins . d"
Answer: D