How many soldiers are there in a group of 27 sailors and soldiers if there are four fifths many sailors as soldiers?

Let the number of sailors be x and the number of soldiers
be y.

Then, given that there are 4/5 sailors as many as
soldiers.

==> y = (4/5)
x.

But, given that all together are
27.

==> x + y = 27.

Let
us substitute with y= (4/5)x

==> x + (4/5)x =
27

==> (9/5)x =
27

==> x = 27*5/9 = 3*5 =
15

Then, there are 15
sailors.

==> y= (4/5)x = (4/5)*15 =
12

Then, there are 12
soldiers.