Find the sum of all the common multiples of 3 and 7 that are less than 51.
Multiples of 3: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45, 48
Multiples of 7: 7, 14, 21, 28, 35, 42, 49
Common multiples of 3 and 7: 21, 42
Sum of all the common multiples of 3 and 7 that are less than 51
= 21 + 42
= 63
Answer(s): 63
