Respuesta :

Answer: 2.5 minutes per call

Step-by-step explanation:

This is a fraction equal to

50 minutes ÷ 20 calls

We want a unit rate where

1 is in the denominator,

so we divide top and bottom by 20

50 minutes ÷ 20

20 calls ÷ 20 =  2.5 minutes/ 1 call