Answer:
He can invite at most 14 friends.
If he invites 14 friends, each friend gets 3 granola bars and 4 fruit drinks.
Explanation:
We need the greatest common factor of 42 and 56.
42 = 2 × 3 × 7
56 = 2³ × 7
GCF = 2 × 7 = 14
The greatest common factor of 42 and 56 is 14.
He can invite at most 14 friends.
42/14 = 3
56/14 = 4