Problema Solution

The sum of three numbers is 48. The sum of the two larger numbers is three times the smallest. The sum of the two smaller numbers is 6 more than the largest. Find the Numbers.----You must set up a system of algebraic equations and solve it.

Answer provided by our tutors

let the numbers be represented by 'a', 'b' and 'c' such as a < b < c


b+c = 3a

a+b = c+6

a+b+c = 48


we subtract the last two equations:

a+b = c+6

a+b+c = 48

to get:

2c = 48-6

c=42/2 = 21


the larger number is 21


now we subtract the first two equations with 'c' replaced by '21'

b+21 = 3a

a+b = 21+6

to get:

a-21 = 27-3a

4a = 48

a = 48/4 = 12


the smallest number is 12


finally, we use the first equation to solve for 'b':

12 + b + 21 = 48

b = 48 - 12 - 21 = 15


the numbers are 12, 15 and 21