Answer: the small bottle holds 15 ounces while the large bottle holds 23 ounces.
Step-by-step explanation:
Let x represent the number of ounces that a small bottle holds.
Let y represent the number of ounces that a large bottle holds.
He drank 2 small bottles and 2 large bottles, for a total of 76 ounces. It means that
2x + 2y = 76 - - - - - - - - - - - - 1
The day before, he drank 4 small bottles and 1 large bottle, for a total of 83 ounces. This means that
4x + y = 83 - - - - - - - - - - - - -2
Multiplying equation 1 by 2 and equation 2 by 1, it becomes
4x + 4y = 152
4x + y = 83
Subtracting, it becomes
3y = 69
y = 69/3 = 23 ounces
Substituting y = 23 into equation 1, it becomes
2x + 2 × 23 = 76
2x + 46 = 76
2x = 76 - 46 = 30
x = 30/2 = 15 ounces
