Calendar Reasoning
17 Class 6 IMO Mathematics Olympiad practice questions on calendar reasoning, part of the Analytical Reasoning topic area. Every question below includes the correct answer and a full explanation.
Practice this topic interactively →1. A leap year has how many days more than a normal year?
- A.0
- B.1
- C.2
- D.3
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Answer: B. 1
A leap year has 366 days, one more than the usual 365.
2. If 15th August is a Thursday, what day is 22nd August?
- A.Wednesday
- B.Thursday
- C.Friday
- D.Saturday
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Answer: B. Thursday
22nd is exactly 7 days after 15th, so it falls on the same day: Thursday.
3. How many days are there in the month of April?
- A.28
- B.29
- C.30
- D.31
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Answer: C. 30
April has 30 days.
4. Which of these months has only 28 or 29 days?
- A.January
- B.February
- C.April
- D.June
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Answer: B. February
February has 28 days in a normal year and 29 in a leap year.
5. If today is Monday, what day will it be 45 days later?
- A.Tuesday
- B.Wednesday
- C.Thursday
- D.Friday
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Answer: C. Thursday
45 ÷ 7 = 6 remainder 3, so 45 days later is 3 days after Monday: Thursday.
6. If 1st January is a Sunday, what day is 1st February? (January has 31 days)
- A.Monday
- B.Tuesday
- C.Wednesday
- D.Thursday
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Answer: C. Wednesday
31 ÷ 7 = 4 remainder 3, so 1st February is 3 days after Sunday: Wednesday.
7. If today is Friday, what day will it be after 10 days?
- A.Sunday
- B.Monday
- C.Tuesday
- D.Wednesday
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Answer: B. Monday
10 ÷ 7 = 1 remainder 3, so 10 days later is 3 days after Friday: Monday.
8. If 1st March is a Tuesday, what day is 1st April? (March has 31 days)
- A.Thursday
- B.Friday
- C.Saturday
- D.Sunday
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Answer: B. Friday
31 ÷ 7 = 4 remainder 3, so 1st April is 3 days after Tuesday: Friday.
9. How many months in a year have 31 days?
- A.5
- B.6
- C.7
- D.8
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Answer: C. 7
January, March, May, July, August, October, and December each have 31 days — 7 months.
10. A year has 365 days. How many full weeks is that, ignoring the remainder?
- A.50
- B.51
- C.52
- D.53
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Answer: C. 52
365 ÷ 7 = 52 remainder 1, so there are 52 full weeks.
11. How many days are there from 5th May to 15th May (counting both dates)?
- A.9
- B.10
- C.11
- D.12
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Answer: C. 11
15 − 5 + 1 = 11 days.
12. If today is Monday, what day will it be 9 days later?
- A.Friday
- B.Wednesday
- C.Thursday
- D.Tuesday
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Answer: B. Wednesday
9 ÷ 7 = 1 remainder 2, so 9 days later is 2 days after Monday: Wednesday.
13. Today is Wednesday. What day was it 100 days ago?
- A.Monday
- B.Tuesday
- C.Sunday
- D.Thursday
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Answer: A. Monday
100 ÷ 7 = 14 remainder 2, so 100 days ago was 2 days before Wednesday: Monday.
14. Today is Sunday. What day will it be after 50 days?
- A.Saturday
- B.Monday
- C.Tuesday
- D.Wednesday
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Answer: B. Monday
50 ÷ 7 = 7 remainder 1, so 50 days later is 1 day after Sunday: Monday.
15. If 10th June is a Monday, what day is 25th June?
- A.Monday
- B.Tuesday
- C.Wednesday
- D.Thursday
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Answer: B. Tuesday
The gap is 15 days. 15 ÷ 7 = 2 remainder 1, so 25th June is 1 day after Monday: Tuesday.
16. If today is Thursday, what day was it 20 days ago?
- A.Thursday
- B.Friday
- C.Saturday
- D.Sunday
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Answer: B. Friday
20 ÷ 7 = 2 remainder 6, so 20 days ago was 6 days before Thursday: Friday.
17. If 26th January is a Sunday, what day is 15th August in the same year? (Assume it is not a leap year.)
- A.Thursday
- B.Friday
- C.Saturday
- D.Sunday
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Answer: B. Friday
From 26 Jan to 15 Aug is 201 days. 201 ÷ 7 = 28 remainder 5, so the day is 5 days after Sunday: Friday.