The average age of a family of 6 members is 22 years.If the age of the youngest member is 7 years,what was the average age of the family at the birth of the youngest member?
a)15
b)18
c)21
d)12

• Answer is: 18
  
  family+7 = 22 x 6
  family = 125
  At youngest one birth family Avg : 90/5 = 18
• 7 years agoHelpfull: Yes(39) No(13)
• a. 15 yrs,
  
  Present age of total members = 6 X 22 = 132
  7 yrs back their ages were = 6 x 7 = 42
  Ages at the birth of youngest member = 132 - 42 = 90
  Therefore, avg age at the birth of youngest member = 90/6 = 15.
• 7 years agoHelpfull: Yes(37) No(20)
• Ans. b) 18
  
  Solution : - Total age of Family = 22 X 6 = 132
  Youngest member age = 7 year
  Age of youngest member at the time of birth = 0 year
  remaining 5 member age is 7 year less at youngest member birth time = 5 X 7 = 35 year
  so total age at youngest member birth time = 132 - 35 - 7 = 90
  Avg. age = 90/5 = 18 ans.
• 7 years agoHelpfull: Yes(16) No(2)
• Present age of total members = 6 X 22 = 132
  7 yrs back their ages were = 6 x 7 = 42
  Ages at the birth of youngest member = 132 - 42 = 90
  Therefore, avg age at the birth of youngest member = 90/6
  (*90 is divided by 6 not 5 bcoz new born baby also consider as a member so its divide by 6)
  ans is 15
• 7 years agoHelpfull: Yes(11) No(4)
• b) 18
  6*22=132
  132-7*6=90
  90/5=18
• 7 years agoHelpfull: Yes(8) No(5)
• present average=22*6=132
  so before his birth ages of all decreases by 7 so average also decreases by 7.
  So the answer is 22-7=15
• 7 years agoHelpfull: Yes(4) No(3)
• At time of birth of youngest member the average age of family members is 18. Since the age 6 members is 22 then the total age of the family members is 6x*22=132. Since the age of youngest is 7 then the average age of family members excluding youngest is 132-7=125(5x). So age of a family member is x=25 after 7 years. Therefore before 7 years age of a family member is 25-7=18. Then 18*5=90 and average age is 18
• 7 years agoHelpfull: Yes(4) No(4)
• average age of 6 members family is 22 that means total age of dis family is 22*6=132,
  now seven years before youngest member was born that means when the youngest mmember was born then total age of dis family was 132-7*6=90;(we have to substract each and every person's age);
  then total age is 90 and number of family members is 6,then average age is 90/6=15 is the answer.....
• 7 years agoHelpfull: Yes(3) No(3)
• b:18
  Present age of total members = 6 X 22 = 132
  7 yrs back their ages were = 6 x 7 = 42
  Ages at the birth of youngest member = 132 - 42 = 90
  now no. of family is 5
  Therefore, avg age at the birth of youngest member = 90/5 = 18
• 7 years agoHelpfull: Yes(2) No(2)
• Assume a,b,c,d,e,f are the ages of each family member and f is the youngest member
  then
  a+b+c+d+e+f=22*6=132
  At present f=7
  So a+b+c+d+e=132-7=125
  At the birth of f total age of family =(a-7)+(b-7)+(c-7)+(d-7)+(e-7)=a+b+c+d+e-35=125-35=90
  So we can easily get the average of the family
  Average Age=90/5=18
  
• 7 years agoHelpfull: Yes(2) No(0)
• a. 15 yrs,
  
  Present age of total members = 6 X 22 = 132
  7 yrs back their ages were = 6 x 7 = 42
  Ages at the birth of youngest member = 132 - 42 = 90
  Therefore, avg age at the birth of youngest member = 90/6 = 15.
  
  @SHAREEF how did you get 90/5 ??
  total members is 6.
  It was asked that at " THE TIME OF YOUNGEST MEMBER NOT BEFORE THE BIRTH OF YOUNGEST MEMBER".. SO YOUNGEST MEMBER IS ADDED IN COUNT.
• 7 years agoHelpfull: Yes(2) No(0)
• b) 18 Years
  
  Let, the total age of the family be x,
  
  Then, Current Average Age (of 6 Members) = 22 (Given)
  
  Thus, x = 22 * 6
  Or, x = 132
  
  Now, if we exclude the age of youngest member i.e. 7 years from the total age of the family
  
  Then, x = 132 - 7 = 125 (of 5 members)
  
  Thus, the Current Average Age of family after excluding the age of youngest member would be
  
  Current Average Year = 125/5 = 25 Years
  
  And, Since the youngest member is 7 years old, Therefore the average age of family at the birth of youngest member would be -
  
  Current Average Age - 7 i.e. 25 - 7 = 18 Years.
  
  Hence, Average Age of the family at the birth of the youngest member was 18 Years.
• 7 years agoHelpfull: Yes(2) No(0)
• the question is little tricky here
  at the time of birth the youngest members age could be taken zero (0) in years if we do in this manner the answer would be 25 years but
  we are not provided with the 25 years option so
  
  age of the youngest member at the time of birth must be taken as 1 year then only we can get an option provided here and i.e.
  
  21 years option (c)
• 7 years agoHelpfull: Yes(0) No(4)
• 7 years ago the sum of age's of 5 members = ((22 * 6) - 7) - 35 = 90
  7 years ago age of youngest member = 0 years
  so
  average age of family 7 years ago = 90 / 6
  = 15 years
  hence option (a) is correct
• 7 years agoHelpfull: Yes(0) No(2)
• avg of6 =22
  6x=132
  5x=132-7
  5x=125
  avg 7 years before=125-35=90
  avg = 90/6=15
  
• 7 years agoHelpfull: Yes(0) No(2)
• ans is 15
  just subtract 7 from average
• 7 years agoHelpfull: Yes(0) No(1)
• Present total age of family=22*6=132
  7 years ago age of 5 people=(132-7-(5*7))=90
  so,the avg age is--> 90/5=18
• 7 years agoHelpfull: Yes(0) No(0)
• 6*22 = sum of ages
  6*22 - 7 = sum of ages of 5 members
  6*22-7-5*7 = sum of ages at time of birth of 6 member
  =6(22-7)
  =6(15)
  Hence answer is A
• 7 years agoHelpfull: Yes(0) No(0)
• 22*6=132
  yongest age is 7yrs
  before 7 yrs age of all=132-7*6=132-42=90
  now avg=90/5=18
• 7 years agoHelpfull: Yes(0) No(0)
• a) 22=total/6
  =>total=22*6=132
  6*7=42=>
  now total age 7 yeas before =>132-42=90
  now new avg=90/6=15
• 7 years agoHelpfull: Yes(0) No(0)
• age of family 6=22
  22years which is including youngest member so. 22-7years
  ans is 15.
• 7 years agoHelpfull: Yes(0) No(0)
• 18....but this will not be an elitmus question
• 7 years agoHelpfull: Yes(0) No(0)
• Answer is:18
  
  average 6 members age is 22.so,total age is 132
  remove the youngest person age from total = 132 - 7= 125
  so, total age of 5 members = 125
  7 yrs back their ages were = 125- (5 x 7) = 90
  At youngest one birth family Avg : 90/5 = 18
  
• 7 years agoHelpfull: Yes(0) No(0)
• The total age of family = 6*22=132
  If we deduct the age of child resulting net age=132-7=125
  The rest 5 members before 7 years will totally deduct =5 members * 7 years = 35 years
  The net age of family now becomes=125-35=90
  the average age of family =90/5=18
• 7 years agoHelpfull: Yes(0) No(0)
• option: b
  Sum of age of all member = 6*22 = 132 yr
  Now, age of 5 member 7 years ago = 7*5 =35 yr
  Sum of age of 5 member at the time birth of youngest people = 132 - (35+7) = 90 yr
  Avg age = 90/5 = 18 yr
• 6 years agoHelpfull: Yes(0) No(0)
• Sum of the ages of 6 members s=6*22 = 132;
  So sum of ages 5 memberes at the birth of the youngest member (sn) = 132 - 7*6 =90
  Avg = 90/5 = 18
  Answer is 18
• 6 years agoHelpfull: Yes(0) No(0)
• Total present age of the family = 6 x 22
  = 132 years
  
  Total age of the family 7 years ago = 132 - 7 x 6
  = 90 years
  
  At that time, the number of members was 5
  ∴ Average age at time = 90 / 5 years
  = 18 years
• 5 years agoHelpfull: Yes(0) No(0)
• Family present+7 =22*6
  Family present =125
  Familybirth =125-7*5=90
  Avg=90/5=18
• 5 years agoHelpfull: Yes(0) No(0)
• 15 is the right answer
• 4 years agoHelpfull: Yes(0) No(0)
• c 125/6= 21
• 3 years agoHelpfull: Yes(0) No(0)