Shoppers at a grand opening for a sporting goods store receive a gift bag when they make a purchase. How often will a bag contain both a T-shirt and socks?
T shirt: Every fourth bag
Socks: Every third bag

Every 12th bag has both a T-shirt and socks.

Step-by-step explanation:

Given: T shirt: Every fourth bag

Socks: Every third bag

Least common multiple of 4 and 3 = 12 as 4 and 3 are coprime (i.e. their highest common factor is 1) and 4 x 3 = 12

It implies every 12th bag has both a T-shirt and socks.

Hence,  Every twelfth bag has both a T-shirt and socks.

b.-4 units

all you   do is count how many times you move