<human>:  Solo has to read 4 pages from his Science textbook, 20 pages from his Social Studies textbook, 7 pages from his History textbook and 8 pages from his Geography textbook. Solo read 15 pages on Monday. If he has 4 more days to complete all his reading, how many pages does he need to read, on average, in one day?
<bot>: How many pages does Solo have to read? ** Solo has to read a total of 4 + 20 + 7 + 8 = <<4+20+7+8=39>>39 pages.
How many pages does Solo have left to read? ** After Monday, he had a remainder of 39 - 15 = <<39-15=24>>24 pages to read.
How many pages does Solo need to read, on average, in one day? ** To complete his reading, he must read 24/4 = <<24/4=6>>6 pages a day.
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