what fraction is topped with sausage?

Question

a pizza has 3 toppings with no toppings overlapping. pepperoni tops 1/3 of the pizza and mushrooms top2/5. the rest is topped with sausage. what fraction is topped with sausage?

Answer 1

Let x = the rest of the pizza (topped with sausage)

 

"3 toppings with no toppings overlapping"  means

   pepperoni         +           mushrooms        +      sausage        =      whole pizza

     1/3                  +                2/5              +        x               =          1

 

We can subtract an equal amount from both sides and get:

         x = 1 - 1/3 - 2/5

 

To get rid of fractions, multiply by the LCM (3*5=15):

        15x = 15 - 5 - 6             or    x = 15/15 - 5/15 - 6/15

                                                   x = (15-5-6)/15

         15x = 4

            x = 4/15             [divide both sides by 15]

 

4/15^ths of the pizza is topped with sausage.