Question

July 3,1970 was a Friday, then July 3,1977 was a:

• A. Sunday
• B. Monday
• C. Saturday
• D. Friday

Answer 1

Answer:

A. Sunday

July 3, 1977 was a Sunday.

1. Count the number of years:
   From July 3, 1970 to July 3, 1977, there are exactly 7 years.

2. Count the leap years in between:
   Between 1970 and 1977, the leap years are 1972 and 1976 (2 leap years).

3. Calculate total odd days:

   • An ordinary year has 1 odd day.

   • A leap year has 2 odd days.

   • Total odd days = (7 years × 1) + 2 extra days for the leap years = 9 odd days.

4. Simplify the odd days:
   Divide 9 by 7 (days in a week). The remainder is 2.

5. Find the day:
   Add 2 days to Friday $\rightarrow$ Saturday, Sunday.