Answer:
He can grade 1.25 assignments in 1 minute.
Step-by-step explanation:
Because the teacher can grade 25 assignments in 20 minutes, we can dive 25 by 20 to get the constant rate.

So he can grade 1.25 assignments in 1 minute.
Answer:
30%. Based on the given conditions, formulate: 12/40 Cross out the common factor: 3/10 Multiply a number.
Step-by-step explanation:
3 2/5 3•5+2 17/5 3.4 11 3/20 223/20 11.15 +3.4=11.15
-3.4 -3.4
= 7.75
7.75+3.6 11.15
11.15=11.15