Explanation:
sqrt(7) is larger than 2 (2² = 4) but smaller than 3 (as 3² is 9).
sqrt(220) is larger than 14 (14² = 196) but smaller than 15 (15² = 225).
so, the integers between them are
3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14
these are 12 integer values.