Answer: 8 and 80
Step-by-step explanation:
8 * 5 = 40
8 * 10 = 80
8 must be the hcf of two separate numbers. So, one of them must be 8, and the other must be greater than 8.
Multiples of 8:
8
16
24
32
40
48
56
64
72
80
The numbers on that list that multiply evenly to 80:
8, 16, 40, 80
16 is the lowest common multiple of 16 and 8
40 is the lowest common multiple of 40 and 8
80 is the lowest common multiple of 80 and 8
So the two numbers are 8 and 80; the highest common factor (HCF) is indeed 8.
