13. In the afternoon, Sonny read 100 pages
at the rate of 60 pages per hour, in the
evening when he is tired, he reads another
100 pages at the rate of 40 pages per hour.
What was his average rate of reading for the
day?
A. 45
B. 48
C. 50
D. 55
To find the average rate of reading for the day, we first need to find the total time Sonny spent reading.
In the afternoon, Sonny reads 100 pages at a rate of 60 pages per hour. Therefore, it took him 100/60 = <<100/60=1.67>>1.67 hours to read in the afternoon.
In the evening, Sonny reads another 100 pages at a rate of 40 pages per hour. Therefore, it took him 100/40 = 2.5 hours to read in the evening.
So, the total time Sonny spent reading for the day is 1.67 + 2.5 = 4.17 hours.
To find the average rate of reading, we divide the total number of pages read (200) by the total time spent reading (4.17 hours).
Therefore, Sonny's average rate of reading for the day is 200/4.17 = <<200/4.17=47.99>>47.99 pages per hour.
Rounded to the nearest whole number, Sonny's average rate of reading for the day is 48 pages per hour.
Answer: B. 48
To calculate Sonny's average rate of reading for the day, you need to find the total number of pages he read and divide it by the total number of hours he spent reading.
In the afternoon, Sonny read 100 pages at a rate of 60 pages per hour. So it took him 100/60 = 5/3 hours to read 100 pages in the afternoon.
In the evening, Sonny read another 100 pages at a rate of 40 pages per hour. So it took him 100/40 = 5/2 hours to read 100 pages in the evening.
Therefore, Sonny spent a total of 5/3 + 5/2 hours reading.
To find the average rate of reading for the day, divide the total number of pages he read (200) by the total number of hours he spent reading (5/3 + 5/2 = 25/6).
So Sonny's average rate of reading for the day is 200 / (25/6) = 200 * 6/25 = 48.
Therefore, the correct answer is B. 48.