Given a math word problem, answer the following question. You might need to apply addition or subtraction mathematical operators on the numbers embedded in the text to answer the question and then only report the final numerical answer.

[EX Q]: debby makes 67 pancakes . she adds blueberries to 20 of them and bananas to 24 of them . the rest are plain . how many plain pancakes are there ?
[EX A]: 23

[EX Q]: in a school there are 542 girls and 387 boys . how many pupils are there in that school ?
[EX A]: 929

[EX Q]: for halloween isabel received 16 pieces of candy from neighbors and 5 pieces from her older sister . if she only ate 3 pieces a day how long would the candy last her ?
[EX A]:
7