SOLUTION: How many soldiers are there in a group of 27 sailors and soldiers if there are four fifths as many sailors as soldiers? Question is from sample test.The answer is 15,but does no

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: How many soldiers are there in a group of 27 sailors and soldiers if there are four fifths as many sailors as soldiers? Question is from sample test.The answer is 15,but does no      Log On


   

Question 185320: How many soldiers are there in a group of 27 sailors and soldiers if there are four fifths as many sailors as soldiers?
Question is from sample test.The answer is 15,but does not make any sense to me.Please help!
For me 4/5 sailors is 21.6 people from that group ,and 1/5 soldiers of 27 is 5.4 people.So I understand that is 22 sailors and soldiers will be 5.
Plesae explain how to solve this problem.Why answer is 15?
Thank you.
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let a = number of sailors
Let b = number of soldiers
Right away, you know there are
less sailors than soldiers, since 4%2F5
is smaller than 1
Suppose you could actually have 4%2F5 of a
sailor? Then %284%2F5%29%2F1+=+a%2Fb would be true
The problem says a+%2B+b+=+27
If a%2Fb+=+12%2F15, then
12+=+%284%2F5%29%2A15 and also
12+%2B+15+=+27