Answer:
145
Step-by-step explanation:
If she did 87 sit-ups in 3 minutes then we would divide 87 by 3 so we know how many sit ups in each minute.
87 divided by 3 is 29
since we want to know how much she would complete in 5 minute we would have to multiply 29 by 5
29x5=145
hope that answers ur question