Suppose today is Sunday, and 75 days later, what day is the week

Suppose today is Sunday, and 75 days later, what day is the week

75 △ 7 is 5, so this bracket is omitted below the 75 and 5 congruences (MOD7)
So 75 ^ 75 is congruent with 5 ^ 75
So 75 ^ 75 is congruent with 125 ^ 25
More than 6
So 75 ^ 75 and 6 ^ 25 congruence and (- 1) ^ 25 congruence and (- 1) congruence, so it's Saturday