Answer:
Shelby did 10,281 sit-ups for 69 days in total.
Step-by-step explanation:
If you multiply or add 149, 69 times you will get 10,281.
If you multiply 149x69= 10,281
Or
Add 149 for 69 times
149+149+149+149+149+149+149+149+149+149+149+149+149+149+149+149+149+149+149+149+ 149+149+149+149+149+149+149+149+149+149+
149+149+149+149+149+ 149+149+149+149+149+149+149+149+149+149+
149+149+149+149+149+ 149+149+149 149+ 149+149+149+149+149+149+149+149+149+149+149+149+149+149+149= 10,281
