What is 35% of 4/13 of 780?
Choose one:
A) 62	B) 73	C) 84	D) 95	E) 106
This problem can be solved easily if we just use approximation: 35% is a little over 1/3, while 4/13 is a little less than 4/12, which is 1/3. Thus, the answer is about 1/3 of 1/3 of 780, or 1/9 of 780. Since the first 1/3 is a slight underestimate and the second 1/3 is a slight overestimate, the errors will partially cancel each other out. Our estimate will be relatively accurate.   The number 780 is between 720 and 810, so (1/9)*780 will be between 80 and 90.   Keeping track not only of your current estimate, but also of the degree to which you have overestimated or underestimated , can help you pinpoint the correct answer more confidently.   The closest answer is 84, so this is the answer to choose.   The answer is 84.
<result>C</result>
What is 35% of 4/13 of 780?