Step 1: 
Find out what the cost is for one can
Streamline market -
1.99/6 = 0.331666666666667
Bulky store - 
6.99/24 = 0.29125
Step 2:
You can check this by getting the streamline market into 24 so -
1.99 x 4 = 7.96 
Step 3:
Answer - 
Bulky store is better to buy Coca Cola as the price for one can is cheaper than streamline market