Explanation

The prime numbers less than 25 are: 2, 3, 5, 7, 11, 13, 17, 19, and 23.

Let's add them up:

2 + 3 = 5

5 + 5 = 10

10 + 7 = 17

17 + 11 = 28

28 + 13 = 41

41 + 17 = 58

58 + 19 = 77

77 + 23 = 100

So, the sum of prime numbers less than 25 is: 100