Problem 16 · 2009 Math Kangaroo
Medium
Arithmetic & Operations
divisionoff-by-one
Today is Sunday. Francis starts reading a 290-page book today. On Sundays he reads 25 pages, and on every other day he reads 4 pages, with no exception. How many days does it take him to read the whole book?
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Answer: E — 41
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Hint 1 of 2
Group the week: one Sunday plus six ordinary days makes a fixed weekly total.
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Hint 2 of 2
Each full week reads 25 + 6×4 = 49 pages; see how many weeks fit into 290.
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Approach: weekly chunks then finish
- A week reads 25 (Sunday) + 6 × 4 = 49 pages.
- After 5 weeks (35 days) he has read 5 × 49 = 245 pages, leaving 45.
- Day 36 is a Sunday (25 pages), reaching 270 with 20 left; then 5 days of 4 pages finish it.
- That is 35 + 1 + 5 = 41 days — answer E.
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