You are given a math word problem and you are supposed to apply an addition mathematical operator on the numbers embedded in the text to answer the following question and then only report the final numerical answer.
Example: Context: 21 children were riding on the bus. At the bus stop 5 children got off the bus while some more got on the bus. Then there were 16 children altogether on the bus. 

 Question: How many children got on the bus at the bus stop?
Example solution: 0
Example explanation: Number of children who got on -> 21 - 5 + x = 16 , x = 0, hence no one got onto the bus

Problem: Context: Rachel had to complete 9 pages of math homework, 11 pages of reading homework and 29 more pages of biology homework. 

 Question: How many pages of math and reading homework did she have to complete?

Solution: 20