Being a multiple of 10 and 20 the number has to end in 0 and be an even number.
That gives you 60 and 80 now see if they are divisible by 4:
60/4 = 15
80:4 = 20
They both are.
The answer would be 60, 80
80 and 60
The numbers in this range that are multiples of 10: 50,60,70,80, and 90
The numbers in this range that are multiples of 20 and 10: 60 and 80
The numbers in this range that are multiples of 20 and 10 and 4: 60 and 80
