Answer:
140
Explanation:
The multiples of 10 are : 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, ...
The multiples of 20 are : 20, 40, 60, 80, 100, 120, 140, ....
The multiples of 14 are : 14, 28, 42, 56, 70, 84, 98, 112, 126, 140, .....
The least common multiple of 10, 20 and 14 is 140