The sum of 3 numbers is 100. The second number is 2 more than three times the 1st number and the 3rd no is the sum of the first two numbers what are the numbers

Sagot :

The numbers are 12, 38 and 50.
the second number is = 2+3a
the third is = a+b

I just used the Trial and Error strategy.
I started with 10, then 11 and so on until I found the answer.

let x= the 1st number
    y=2nd number
    z=3rd number
equations: x + y + z = 100 -----> eq.1
                y = 2 + 3x -------> eq.2
                z = x + y  ---------> eq.3
substitute eq. 2 to eq.3 : z= x + 2 + 3x
                                     z= 2 + 4x     -----> eq.4
substitute eq. 2 and eq. 4 to eq.1 : x + 2 + 3x + 2 + 4x= 100
                                                        8x + 4= 100
                                                              x = 12
substitute the value of x to eq. 2: y= 2 + 3(12) 
                                                 y= 38
substitute the value of x and y to eq. 3: z = 12 + 38
                                                          z = 50

the numbers are 12, 38 and 50.