Three friends share a bag of erasers. Mary get 1/5 of the eraser. Helen gets 3 more erasers then mary and Sylvia gets 12 erasers. How many erasers are in the bag

?

4/5 of the share belongs to Helen and Sylvia

Difference in total share is = 4/5-1/5

=3/5

So 3/5=12+3

=15

3 units is 15

Thus 1 unit is 15/3 which is 5

And 5 units is 25 (5*5)

I am not too sure though

Sorry