Mariano delivers newspapers. he always puts 3/4 of his weekly earnings in his savings account and then divides the rest equally into 3 piggy banks for spending at the snack shop, the arcade, and the subway.
a. what fraction of his earnings does mariano put into each piggy bank?
b. if mariano adds $2.40 to each piggy bank every week, how much does mariano earn per week delivering papers?

a. Fraction of earnings that Mariano put into each piggy bank  is 1/12

b. Mariano earns $28.8

Step-by-step explanation:

Mariano divides his earning in a saving account and 3 piggy banks.  

First ,  we have to know the fraction that we divide in the 3 piggy banks.

Piggy banks =Total earning-Saving account

Saving account 3/4,  

Total earning is 1

to rest both term we have to get the same denominator , so we can say that the total earning is 4/4

Piggy banks =4/4-3/4=( 4-3)/4=1/4

Piggy banks =1/4

Each piggy bank will be 1/3 of that 1/4

1/3 x 1/4=

For fraction multiplication, multiply the numerators and then multiply the denominators to get

1×1/3×4=1/12

This fraction cannot be reduced.

b. Mariano adds $2.40

1/12 is 2.40

total earning  is ?

We use cross-multiplication

a/b=c/d  replacing   (1/12)/2.40 = 1/ ?

So,  the total earning (?) is 1 x 2.40/ (1/12)

= 2.40 x 12=$28.8