Answer:
90 pizzas
Explanation:
We know that 9/10 of the pizzas are Hawaiian, and the other 1/10 are vegetarian. There are 72 more Hawaiian pizzas than vegetarian pizzas. It's the 72 that's important here. We know 9/10 are Hawaiian and the other tenth are vegetarian. Subtract 1/10 from 9/10 to get 8/10.
(9 - 1)/10
8/10
As a result, 72 is 8/10 of the total. Now divide 72 by 8/10. That is the same as 72 times 10/8.
72 / 8/10
72/1 * 10/8
9/1 * 10/1
9 * 10
There are 90 total pizzas in the pizza shop.