Find the ratio between 1hr 30 minutes and 2hrs 40 minutes.  Choose the correct choice from the following answers
A) 9 : 16	B) 5 : 9	C) 12 : 17	D) 13 : 24	E) none of these

Rationale: solution : the ratio = 1 hr 30 min : 2 hr 40 min . 90 min : 160 min = 9 : 16 . answer is a
Answer: A