Question

A bottle of ink was 2/3 full.When 7 pens were filled with ink from the bottle and 2 pens full of ink was poured into it, it was 1/4 full.How many pens can be filled with the full bottle of ink?

Answer 1

If the bottle holds b and a pen holds p, then we are told

2b/3 - 7p + 2p = x/4
5b/12 = 5p
b = 12p