Question

your mother gave you $13.32 cents with which to buy a present. this covered 3/5 of the cost. how much did the present cost

Answer 1

Please forgive me if i'm wrong. I have two different way to go this. They both are different answer.
 
 First Solution:

How much money I have: $13.32 

How much it cost: 3/5 = 75%
 
I had learned something at school called (is, of equal percent).

$is \frac {x}{13.32} = \frac{75}{100} percent of$
       
 
How to solve:
when do the first hundred, cross out the $\frac{100x}{100}$ and bring the one-hundred down then divide your new numerator and denominator.
     
$\frac{100x}{100} = \frac{999}{100}$ = $9.99

Answer ; $9.99
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Second Solution: 

I also learned something call (the double number line).

Dollar 13.32    26.64     39.96 ________
Cost      1___     2____    3______

Answer: $39.96

Answer 2

The best thing to do is to find out what 1/5 is equal to, and you can do this by dividing $13.32 by 3
13.32/3= 4.44
Therefore, 1/5 = $4.44
As you're looking for the total amount, you multiply this by 5.
$4.44*5= $22.20
Therefore, the present cost $22.20
Hope this helps :)