Answer:
Third week, 15 words per minute
Step-by-step explanation:
First week: 10 words per minute
Second week
10 * 20% = 10*.2 = 2
It is an increase, so we add the 2 to the original amount
10+2 = 12 word per minute
Third week
12 * 25% = 12 *.25 = 3
It was an increase, so we add the 3 to the amount in week 2
12+3 = 15 words per minute