What is meant by "evenly divisible"? "What is the smallest positive number that is evenly divisible by all of the numbers from 1 to 20?"
Is it different from divisible?
Evenly divisible means that you have no remainder. 
So, 20 is evenly divisible by 5 since 20 / 5 = 4.
Though, 21 is not evenly divisible by 5 since 21 / 5 = 4 R 1, or 4.2.
Means the same as "divisible". Answer is $2\times3\times5\times7\times11\times13\times17\times19$.