Answer:
900 batteries
Step-by-step explanation:
First we must find how many batteries does 1 calculator need
we can do this by dividing 160 by 40
which will give us 4 batteries per calculator
then we multiply the amount of calculators we have with 4
225×4 = 900 so we need 900 batteries
Yes 90 is 1/10 of hundred
You should suck a long rod and the answer is around 50 minutes