50 + 20h = 100 + 10h
20h - 10h = 100 - 50
10h = 50
h = 50/10
h = 5 <== they will charge the same at 5 hrs
Answer: 5 cookies
Step-by-step explanation: 8 + .4c = 2.5 + 1.5c
8 + 0.4c = 2.5 + 1.5c
8 · 10 + 0.4c · 10 = 2.5 · 10 + 1.5c · 10
80 + 4c = 25 + 15c
4c = 15c - 55
4c - 15c = 15c - 55 - 15c
-11c = -55
c = 5
I think it’s the third option