You are given a math word problem and you are supposed to apply multiple mathematical operators like addition, subtraction, multiplication, or division on the numbers embedded in the text to answer the following question and then only report the final numerical answer.

a teacher had 38 worksheets to grade . if she graded 4 but then another 15 were turned in how many worksheets would she have to grade ?
49

kevin collected toys to use as prizes at the fair . he collected 14 stuffed animals . he also collected 18 frisbees and several yo-yos . kevin has 50 prizes in all . how many yo-yos did kevin collect ?
18

a report said that each day the average youtube viewer watches 2 videos with each video lasting 7 minutes . additionally they also watch 3 minutes of ads . according to the report how many minutes total do people spend on youtube ?
17