step 1
Find out the expected value
In this game, the total possible outcomes are 12
The probability of a win is P=1/12
The probability of loss is P=11/12
so
EV=(1/12)*(30-20)-(11/12)*30
EV=(1/12)*(10)-(11/12)*30
EV=(10/12)-(330/12)
EV=-320/12
EV=-26.67p ----> is negative because is a loss for the players
If 60 people play the game
26.67*60=1,600
therefore
The school expect to raise for charity 1,600p
Divide by 100
