what is the sum of all prime numbers less than 10? 0 P r i m e n u m b e r s l e s s t h a n 10 a r e , 2 , 3 , 5 , 7 A n d t h e i r s u m = 2 + 3 + 5 + 7 = 17 1 View Full Answer The sum of all prime no.s below 10 is 17. 1 17 1 17 -1