The sum of three number is 15. If the second number is subtracted from the sum of first and third number then we get 5 an if twice of first number is added to second and if the third number is subtracted from the sum we get 4.
Let the three numbers be a,b,c
The sum of three numbers is 15
⟹a+b+c=15⋯(1)
The second number is subtracted from the sum of first and third number to geet 5
⟹a−b+c=5⋯(2)
twice of first number is added to second and if the third number is subtracted from sum we get 4
⟹2a+b−c=4⋯(3)
(1)−(2)
⟹2b=10b=5
put it in (1)
⟹a+c=10c=10−a
put it in (3)
2a+5−10+a=43a−5=43a=9a=3⟹c=10−3c=7a=3;b=5;c=7