in a shopping mall with staff of 5 members, the average is 45.After 5 years a person joined them and the average is again 45. what is the age of 6th person?

• Since the average age is 45 yrs for the 5 members.
  sum total of their ages = 45 X 5=225 yrs.
  after 5 years, sum total of their ages = 225 + ( 5 X 5 ) = 250 yrs
  now , let x be the age of the 6th person, so
  the sum total of age is now = (250 + x ) yrs.
  given the average is 45 yrs.
  so,
  ( 250 + x )/ 6 = 45
  or, x = 20 yrs.
  so, the age of the 6th person is 20 years.
• 11 years agoHelpfull: Yes(22) No(0)
• he multiplied because he is adding age of 5 members after 5 years so (5*5)
• 11 years agoHelpfull: Yes(2) No(0)
• let sum of 5 members age are A then
  A=5*45=225
  now after 5 year the age of old 5 are A+25 and age of 6 is x
  250+x=45*6
  x=20
  so the 6th person age is 20 year
• 11 years agoHelpfull: Yes(2) No(0)
• 5*45+5*5+x/6 = 45
  x= 20
  
• 11 years agoHelpfull: Yes(1) No(0)
• @surabh:after 5 years means u shd add but u multiplied...y?
• 11 years agoHelpfull: Yes(0) No(1)
• @chinna: I hope M.Sridevi has made it clear to you.
• 11 years agoHelpfull: Yes(0) No(0)
• let the age age of the new person be x.
  After 5 years the average of the 5 persons will also change.
  So, the average of the 5 persons becomes
  45+(5*5/5)=50
  After 5 years the average of the 5 persons becomes 50
  Now a new person is included and the average becomes 45
  now see what is the new average and how much it is less or more from the old average.
  In this case the
• 11 years agoHelpfull: Yes(0) No(3)