Question

A full can of milk weighs 70 pounds. If exactly half of the milk is poured out, it weighs 38 pounds. How much does the empty can weigh?

Answer 1

6 pounds

Explanation:

Let the can weigh x pounds

Let the milk weigh y when full, therefore half is
`(y)/(2)`

Now we for 2 simultaneous equations:

`x + y =70` ....(i)

`x+ (y)/(2)= 38` .... (ii)

we solve by eliminating the x in both equation throug subtraction

`x - x + y- (y)/(2) =70-38\\y- (y)/(2) = 32\\(y)/(2) = 32\\y=2(32)\\y=64\\x+y=70\\x+64=70\\x=6`