Answer:
5
Step-by-step explanation:
Find the greatest common divisor:
gcd(20, 45, 15)
Find the divisors of each integer and select the largest element they have in common:
The divisors of 20 are:
1, 2, 4, 5, 10, 20
The divisors of 45 are:
1, 3, 5, 9, 15, 45
The divisors of 15 are:
1, 3, 5, 15
The largest number common to all divisor lists is 5:
divisors of 20: 1, 2, 4, 5, 10, 20
divisors of 45: 1, 3, 5, 9, 15, 45
divisors of 15: 1, 3, 5, 15
Answer: gcd(20, 45, 15) = 5
