Question 269611
Let calories in the sandwich = S cal.
Let calories from the glass of milk = M cal.

S + 2M = 600 Cal. 

Now Sandwich has 2.4 times more calories than a glass of milk.
it means  S = 2.4 M.

Replace S with 2.4M in the first equation.

S + 2M = 600 Cal.
2.4 M + 2M = 600 Cal.
4.4 M = 600 Cal. 
M = (600/4.4) Calories
So one glass of milk has (600/4.4) calories and
Sandwich  has (600/4.4) * 2.4 calories.