1 cartons of juice = $4.20
3 single cartons = 4.20 * 3 = $12.60
1 pack = $9.45
He saved 12.60 - 9.45 = $3.15
So, he saved $3.15, compared to the total ($12.60)
To calculate the percentage, we will do a proportion:
3.15 (money saved) : 12.60 (total of 3 single cartons) = x (how much percentage) : 100 (total)
3.15 : 12.6 = x : 100
To calculate x, we will moltiplicate the ends (where we have known numbers) than divide all per 12.6
So
x = (3.15 * 100) / 12.60 = 315 / 12.6 = 25
So the percentage saving is 25%
