Answer:
5 pizzas.
Explanation:
Find out how many slices the group of 10 people need in total:
2 x 10 = 20 slices
Now, use the total number of slices and divide it with 4 to find how many pizzas they need.
20 รท 4 = 5
They need 5 pizzas for 10 people who each get 2 slices.