The Jones's and the Johnsons want to see who sleeps more, women or men. The Jones family has 1 female and 3 males. On the night of the test the Jones family slept a total of 43 hours. The Johnson family has 3 males and 4 females and their total sleep was 60.72 hours.

How many hours does each male and female sleep, assuming that all males sleep the same amount of hours and all females sleep the same amount of hours.

Ok, cool.

So...

3x+y=43

3x+4y=60.72

Then...

5y=103.72

then...

y=20.74

Then when I substitute it it comes out wrong. Have I already made a mistake?

Could someone please just help me through this?