To check, we can solve how much sunscreen is in a family sized bottle first. We need to find what is 20% of 12. First, turn 20% into a decimal: 20%/100= 0.2. Now, multiply 0.2 by 12, which is 2.4. Then, you add this to 12 because it is 20% more. 12+2.4= 14.4. Multiply this by 4: 14.4*4=57.6. Since his number is close to 50, he is kinda correct, but a much more reasonable answer would be closer to 60. Hope this helped!
