Answer:
Friday and Saturday
Explanation:
No. of days in April = 30
No. of days in one week = 7
So, if we divide 30 by 7 we get 4 as a quotient and 2 as a remainder
Quotient 4 shows that every day of the week will occur at least 4 times. And the remainder 2 shows that any 2 days of the week will occur 5 times.
Now for month April to have exactly 4 Saturdays, last 2 days must not be : Friday Saturday or Saturday Sunday because in this case the Saturday will occur 5 times.
So, For April to have exactly 4 Saturdays , April 1 may not have occurred on Friday or Saturday because in both the cases the Saturday will occur 5 times.
Hence, the required days of the week are : Friday and Saturday