# Thread: Help with a math problem

1. ## Help with a math problem

Hi!

My first post here. I hope I am posting this question in the right place
I need help with a problem and it goes something like this:

A man is selling soda. He has two types of bottles for sale: One that contains 1 litre and one that contains three litres.
The bottles that contains one litre costs 50 money
The bottle that contains three litres costs 130 money
When the day is over he has sold bottles for 9240 money.
He sold a total of 100 bottles.
How many litres has he sold?

English is not my first language, but i hope you understand anyway

2. Originally Posted by AknightwhosayNi
Hi!

My first post here. I hope I am posting this question in the right place
I need help with a problem and it goes something like this:

A man is selling soda. He has two types of bottles for sale: One that contains 1 litre and one that contains three litres.
The bottles that contains one litre costs 50 money
The bottle that contains three litres costs 130 money
When the day is over he has sold bottles for 9240 money.
How many litres has he sold?

English is not my first language, but i hope you understand anyway
Let the number of 1L bottles be x and the 3L bottles be y:

50x + 130y = 9240

3. That was what I was beginning to suspect. Thanks anyway.

4. I missed some information, and corrected the error now. I still need help solving he problem though, and i would really appreciate your help

A man is selling soda. He has two types of bottles for sale: One that contains 1 litre and one that contains three litres.
The bottles that contains one litre costs 50 money
The bottle that contains three litres costs 130 money
When the day is over he has sold bottles for 9240 money.
He sold a total of 100 bottles.
How many litres has he sold?

5. That's better, now you have two equations with two unknowns:

50x + 130y = 9240
x + y = 100

Let's solve by substitution. Solve the second equation for x:
x = 100 - y

Substitute that into the first equation:
50(100 - y) + 130y = 9240
5000 - 50y + 130y = 9240
5000 + 80y = 9240
80y = 4240
y = 53

Now substitute this back into the modified 2nd equation to find x:
x = 100 - y
x = 100 - 53
x = 47

So the man sold 47 1L-bottles of soda and 53 3L-bottles of soda, for a total of 206 liters.

01

6. Thanks