If it is Friday on 4/8/2017, then what day will it be after 61 days?

Concept

Weekdays repeat in a cycle of seven days.

Dividing an interval by 7 separates complete weeks from the remaining forward shift. Complete weeks return to the same weekday.

Application

1. Divide 61 by 7: 61 = 8 × 7 + 5, so there are eight complete weeks and five extra days.

2. The eight complete weeks bring the cycle back to Friday.

3. Count the five extra days forward from the day after Friday: Saturday (1), Sunday (2), Monday (3), Tuesday (4), Wednesday (5).

Cross-check

After 56 days (eight weeks), it is Friday again; moving five more days reaches Wednesday.

Therefore, the day after 61 days will be Wednesday.