In the afternoon, a student read 100 pages at the rate of 60 pages per hour. In the evening, when he was tired, he read 100 more pages at the rate of 40 pages per hour. What was his average rate of reading of pages per hour?

48

Afternoon

100 pages read at the rate 60 pages per hour

Total time taken to read 100 pages = \(\frac{100}{60}\) = \(\frac{5}{3}\) hour

Evening

100 pages read at the rate 40 pages per hour

Total time taken to read 100 pages = \(\frac{100}{40}\) = \(\frac{5}{2}\) hour

Average rate of reading the pages per hour = \(\frac{Total \; pages}{Total \;time}\)

                                                                      = \(\frac{200 × 6 }{10 + 15}\) =  \(\frac{1200 }{25}\) = 48