It is: 90
The number 20 is.
To be a multiple of 4, 10 and 20 the number must be a multiple of their lowest common multiple. lcm(4, 10, 20) = 20 What is required is a multiple of 20 between 61 and 107. The numbers 80 and 100 both satisfy the problem of being between 61 and 107 and being a multiple of 4, 10 and 20.
CXIII = 113 (100+10+1+1+1 = 113)
13
13 is a prime number in that range. So are 11, 17 and 19.
There are none.
It is 70
It is: 90
90 is.
It is: 90
80 and 100 both qualify.
Good luck. The LCM is 290.
It is 84.
80
80 and 100 are the only numbers between 67 and 113 that are multiples of 4,5 and 10.
Just 90
Only 80.