There are 16 cups in 1 gallon so you would have to turn the denominator in the fraction into a 16 meaning you would multiply by 4 (because 4 goes into 16, 4 times). Your new fraction is 12/16. now you do 6 gallons*16 cups and you get 96 cups. Then you add the fraction onto 96 and you would be adding 12. Your final answer is 108 cups in 6 3/4 gallons
Is that the whole question ?
Given: The information provided in the table shown
To Determine: From the options provided, the correct option that best describe the information given in the table
Solution
Given that 28% of the children used toothpaste. From the table

Let us calculate the percentage of adult that used toothpaste

Hence, a smaller percentage of adults (about 11%) use the toothpaste.
The correct option is OPTION C
Move the x's to the same side
2x + x = 8 +6
then simplify
3x = 14
make x stand on its own
(3x)/3 = 14/3
the 3's on the x side cancel
x = 14/3