Question

Ashley found 78 rocks on Monday. on Tuesdays Devin found 45 rocks how many did the find both days

Answer 1

Lets look at the info we have:-

Ashley found 78 rocks on Monday.
Devin found 45 rocks on Tuesday. 

Question:-

How many did they find both days?

The key word for this is "both". So we need to add here. Lets add:-

78 + 45 = 123

So, Ashley and Devin together found 123 rocks.

Hope I helped ya!! xD