Yes, 20 x 2 = 40.
40 is divisible by 1, 2, 4, 5, 8, 10, 20 and 40.
The number is 40.
2
No number between 20 and 40 is divisible by all 4 numbers. The smallest number divisible by all 4 of those numbers is: 56
40 is an even number - it is divisible by 2 to produce a whole number
40*36 = 1440 is divisible (not divisable) by both. It is not the samllest such number, but that was not required by the question.
25 is the number not less than 20, not greater than 40, not divisible by 2 3 or 7, and not a prime number.
56.
36
36
What we want to find is the number in that list that is not divisible by 4. This number would be 18, your answer.
No. The smallest number divisible by both 5 and 2 is their lowest common Multiple (LCM) which is 10; ALL multiples of their LCM are divisible by 5 and 2, ie 10, 20, 30, 40, 50, ... are all divisible by 5 and 2.