A small company with three bricklayers is hired to build a barbecue. Each worker can lay a certain integer number of bricks per minute. The company could assign any combination of 1, 2 or all 3 workers to the job, and each combination would complete the barbecue in a different integer number of minutes.
What is the minimum number of bricks in the barbecue?
1,2,4 is the smallest triplet enabling forming
distinct teamings i.e. from 1 to 7.
smallest number divisible by each of the above numbers is 2*5*6*7= 420