Reasoning Ability - Calendar Problems
A person born on 15th August 1975 had his 45th birthday on a Saturday. What day of the week was he born?
A person born on 15th August 1975 had his 45th birthday on a Saturday. What day of the week was he born?
medium Q15 of 15
Step-by-Step Solution
Step 1: Duration
15 Aug 1975 → 15 Aug 2020 = 45 years.Step 2: Count leap years
Leap years between 1976 and 2019: 1976,80,84,88,92,96,2000,04,08,12,16 → 11 leaps.Step 3: Compute total odd days
Ordinary = 45 − 11 = 34 → 34 × 1 = 34; Leap = 11 × 2 = 22; Total = 56 → 56 mod 7 = 0 odd days.Step 4: Back-calculate birth weekday
45th birthday = Saturday. Birth weekday = Saturday − 0 = Saturday.Final Answer:
Saturday → Option AQuick Check:
0 remainder → same weekday → Saturday ✅
Quick Trick: If total odd days ≡ 0, weekday stays the same on that anniversary.
Common Mistakes:
MISTAKES- Forgetting to include the century leap year 2000 in the leap count.
Master "Calendar Problems" in Reasoning Ability
Start learning the concept with an interactive lesson.
Want More Practice?
15+ quiz questions · All difficulty levels · Free
Free Signup - Practice All QuestionsMore Reasoning Ability Quizzes