Maths-word problems

Today in maths we were coming up with word problems. Each table group created their own word problem and the rest of the class had to try and solve it; we got one that we thought should be a GCSE question because it was so difficult. Despite the hard work, Callum managed to solve the question - however, everyone persevered and didn't give up, we were desperate to come up with the answer. This is the question, without a calculator can you get back to us with the answer?