Amount of carbs in one glass of milk is 13 and amount of carbs in one snack bar is 14
Let "m" be the amount of carbs in one glass of milk
Let "s" be the amount of carbs in one snack bar
Given that two glasses of milk and 3 snack bars have a total of 68 carbs
carbs in one glass of milk x two glasses of milk + carbs in one snack bar x 3 snack bars = 68 carbs
2m + 3s = 68 ---- eqn 1
Similarly,
Also given that 4 glasses of milk and 2 snack bars have a total of 80 carbs
4m + 2s = 80 ------ eqn 2
Let us solve these two equations and find values of "m" and "s"
Multiply eqn 1 by 2
4m + 6s = 136 --- eqn 3
Subtract eqn 2 from eqn 3
4m + 6s = 136
4m + 2s = 80
(-) ----------------------
4s = 56
s = 14
Substitute s = 14 in eqn 1
2m + 3s = 68
2m + 3(14) = 68
2m = 26
m = 13
Thus the amount of carbs in one glass of milk is 13 and amount of carbs in one snack bar is 14