Question

The sum of three consecutive odd numbers is 20 more than the first number among three.what is the middle number?

Answer 1

lets consider three consecutive numbers are n+1 n+3 and n+5

sum= n+1+n+3+n+5 = n+1+20

    3n+9=n+21

2n=12   n=12 so middle number is n+3 = 12+3 =15

Answer 2

let the three consecutive odd numbers be x  ,  [x +2] , [x+4]

ATP

The sum of three consecutive odd numbers is 20 more than the first number

⇒x  + [x +2] + [x+4]  =20 +x

⇒x + x +2 + x+ 4 =20+x

⇒x+x+x-x +6 =20

⇒2x =20-6

⇒2x  =14

⇒x =7............................... First nos.     ANS  =  7

⇒[x +2 ] = 7+2 =9 ...........second nos.ANS  = 9

⇒[x +4 ] = 7+4 =11 ...........third nos.    ANS =11