Problem Solving

what could be possibly an approach to quickly solve this problem?

Hi,

You don't really have to do the math on this one, if you just think about it logically.

Moving from left to right:

6/7 is a bit bigger than 5/6, so 6/7 - 5/6 will bring us to a small fraction greater than 0. 4/5 is a bit smaller than 5/6, so when we add 4/5 back in, we go above the 1/2 mark but certainly not above 1. 3/4 is a bit smaller than 4/5, so when we subtract 3/4 out we are going back down into small fraction land. 2/3 is smaller than 3/4, so when we add 2/3 back in, we get back up to the more than 1/2 range. 1/2 is less than 2/3, so we are going back down into the smaller fraction area.

Thus, the answer choice is greater than 0 but less than 1/2.

Cheers,