Given:
4/5 of a pie left after their family picnic.
Each slice of pie was 1/15 of the total pie.
To find:
The number of remaining slices of pie.
Solution:
Let x be the number of remaining slices of pie.
Part of total pie in one slice =
Remaining part of total pie in x slices =
According to the question, 4/5 of a pie left after their family picnic.
Using cross multiplication, we get
Divide both sides by 5.
Therefore, the remaining number of slices of pie is 12.