Start by finding the reading time in the second week of the program.
C
Practice makes perfect
We want to find in what week of the program the students began reading for an hour per day. We know that they read 20 minutes per day during the first week. They increased their reading time by 50 % each week after that. For example, the reading time in the second week equals the reading time in the first week plus 50 % of the reading time in the first week.
Week
Reading Time, min
1
20
2
20 + 50 %of 20
Let's calculate the reading time in the second week by simplifying the expression from the table. To make multiplying 50 % by 20 a little bit easier, remember that 50 % is equal to 12.
We found that the students read for 30 minutes per day in the second week.
Week
Reading Time, min
1
20
2
20 + 50 % * 20 = 30
This means that the students did not begin reading for an hour per day in the second week. Next, let's find the reading time in the third week using the same method as we did to find the reading time for the second week.
Week
Reading Time, min
1
20
2
30
3
30 + 50 % * 30
Let's simplify the expression to calculate the reading time in the third week.
The reading time in the fourth week was 67.5 minutes per day, which is more than an hour per day. This means that the students began reading an hour per day in Week 4. Therefore, the correct option is C.
