There are 20 students with an average height of 105 cms in a class. Then 10 students with an average height of 120 cms join the class. What will be the average height of the class now?

• 20 students average height is 105cms
  sum of heights/ 20 =105cms
  sum of heights of 20 students= 105*20= 2100
  10 students of average height 120 added
  so their, sum of 10 students height / 10 = 120
  sum of heights of 10 students = 1200cms
  By adding heights of 20 and 10 students , 1200+2100 = 3300
  average of 30 students = 3300/30 = 110 cms
  
  Answer is 110 cms
• 9 years agoHelpfull: Yes(21) No(0)
• 105*20=2100
  120*10=1200
  Total AVG=2100+1200=3300
  Total no.of Students=30
  So 3300/30=110
  
• 8 years agoHelpfull: Yes(4) No(1)
• total height of 30 student = 20*105+10*120/30
  =2100+1200/30
  =3300/30
  =110
  
• 8 years agoHelpfull: Yes(1) No(0)
• Total height of 20 students=20*105=2100
  new student total height=10*120=1200
  now, average=(2100+1200)/30=110.
• 8 years agoHelpfull: Yes(1) No(0)
• 20 students avg height 105 : 20*105=2100
  10 students avg height 120 : 10*120=1200
  total height of all students= 2100+1200=3300
  total number of students=30
  avg height of the class is 3300/30=110
  
  
• 8 years agoHelpfull: Yes(1) No(0)
• Average Height = Sum of heights of all students/Total no of student
  Total Students in class= 20+10 = 30
  Now
  20 students has average height of 105 cm
  so sum of height of 20 students is = 20*105=2100 cm
  
  10 students has average height of 105 cm
  so sum of height of 10 students is = 10*120=1200 cm
  
  Sum of heights of all students = Sum of height of 20 students + Sum of height of 10 students
  = 2100 cm + 1200 cm
  = 3300 cm
  
  Average Height = 3300 cm/30 = 110 cm
  
• 8 years agoHelpfull: Yes(1) No(1)
• Average Height = Sum of heights of all students/Total no of student
  Total Students in class= 20+10 = 30
  Now
  20 students has average height of 105 cm
  so sum of height of 20 students is = 20*105 cm=2100 cm
  
  10 students has average height of 120 cm
  so sum of height of 10 students is = 10*120 cm=1200 cm
  
  Sum of heights of all students = Sum of height of 20 students + Sum of height of 10 students
  = 2100 cm + 1200 cm
  = 3300 cm
  
  Average Height = 3300 cm/30 = 110 cm
• 8 years agoHelpfull: Yes(1) No(0)
• ans is 110
• 8 years agoHelpfull: Yes(1) No(0)
• (20*105+10*120)/30=110
• 8 years agoHelpfull: Yes(0) No(0)
• sum of 20 studnts=20*105=2100
  sum of 10 studnts=10*120=1200
  total sum is 2100+1200=3300
  avrg=3300/30=110cms
• 8 years agoHelpfull: Yes(0) No(0)
• 20 students avg height is 20*105
  Then after join 10 members new avg is 20*105+10*120=3300
  Then avg is 3300/30=110cms.
• 8 years agoHelpfull: Yes(0) No(0)
• (20*105+10*120)/30=110 Cm.
• 8 years agoHelpfull: Yes(0) No(1)
• 110
  x/20=105 =>2100
  y/10=120 =>1200
  total 30 students and height 3300=> avg=3300/30=110
• 8 years agoHelpfull: Yes(0) No(0)
• 20*105=2100
  10*120=1200
  the average height of the total class is=2100+1200/{20+10}=3300/30=110
• 8 years agoHelpfull: Yes(0) No(0)
• 10 students have 15 cms more height than the average height of 20 students.
  Totally they are 150 cms more height than the 20 students height
  Distribute 150 between total 30 students.
  Each get 5 cms. Add 5 cms to avg height
  105+5=110 cms
  
• 8 years agoHelpfull: Yes(0) No(0)
• sum of 20 students=105*20=2100
  sum of 10 students=120*10=1200
  average of 30 students=2100+1200/30
  =330/3
  =110
• 8 years agoHelpfull: Yes(0) No(0)
• ans 110
  
  (20*105+10*120)/(10+20)=110
• 8 years agoHelpfull: Yes(0) No(0)
• There is two categories of students in the class room like (average height) 105 cms, and 120 cms.
  The answer is (105+120)=225/2= 112.5cms
  Ans;- 112.5 cms
• 8 years agoHelpfull: Yes(0) No(4)
• 110 cms
  total 3300/30 so the answer is 110cms
  
• 8 years agoHelpfull: Yes(0) No(1)
• total wt of 20 studs = 105 * 20 = 2100 cms :( total/20=105)
  total weight of newly joined 10 students =1200 cms : ( x/10=120)
  new total weight of 30 students = 2100+1200 = 3300cms
  their average weight (30 students) = 3300/30 =110 cms
  
• 8 years agoHelpfull: Yes(0) No(1)
• Avg=sum of observation / No of observation
  sum of 20 student/20=105
  sum of 20 student=20*105=2100
  sum of 10 student/10=120
  sum of 10 student=120*10=1200
  total avg=1200+2100=3300
  so avg height = 33300/30 = 110 {*20+10=30)
  ans=110
  
• 8 years agoHelpfull: Yes(0) No(1)
• 105*20+120*10
  3300/30=110
• 8 years agoHelpfull: Yes(0) No(1)
• total height of 20 students=20*105=2100
  next 10 students are added.
  therefore total height of 10 students=10*120=1200
  total height of 30 student=2100+1200=3300
  therefore average height=3300/30=110(ans).
• 8 years agoHelpfull: Yes(0) No(0)
• 110
  20*105+10*120/30
  330/30=110
• 8 years agoHelpfull: Yes(0) No(0)
• ANS :) 110
• 7 years agoHelpfull: Yes(0) No(1)
• 20*105=2100
  10*120=1200
  total=3300
  avg of 30 stds=3300/30
  answer:110
• 7 years agoHelpfull: Yes(0) No(0)
• (20*105+10*126)/20+10=(2100+1200)/30=110
• 6 years agoHelpfull: Yes(0) No(0)
• 20*105=2100
  10*120=1200
  (2100+1200)/20+10=110
• 6 years agoHelpfull: Yes(0) No(0)