The total mass of 2 boxes and 4 crates of onions is 130 kg. Given that the mass of a box of onions is 3/5 of the mass of a crate of onions, what is the mass of a box of onions?
2x + 4c = 130 or
x + 2c = 65
x =3/5 c
sub into other equation
3/5 c + 2c = 65
13/5 c = 65
c = 65*5/13 = 25
then x = 3/5*25 = 15
a box has a mass of 15 kg, and a crate has 25 kg