Question

There are 7 people in a group named as A, B, C, D, E, F and G. Average weight of A, B, C and D is
73kg. Average weight of D, E, F and G is 75kg. If the weight of D is 81kg, then what is total average
of all 7 people?​

Answer 1

73*4=292-81=211, and 211 age total a,b,c

75*4=300-81=219 and 219 age total e,f,g so ,

211+81+219=511/7=73 and 73 is right ans. thanks

Answer 2

Average weight of 7 people = 73  kg  

Given:

There are 7 people in a group named as A, B, C, D, E, F and G

Average weight of A, B, C and D is 73kg

Average weight of D, E, F and G is 75kg

The weight of D is 81kg

To find:

what is total average of all 7 people

Solution:

As we know

Average = sum of observations/ number of observations

⇒ Sum of observations = Average × No. of observations

Given that

Average weight of A, B, C and D = 73kg

⇒ Sum of weights of A, B, C and D = 73× 4 = 292 kg

⇒ Sum of weights of A, B, C = 292 - 81 kg = 211 kg   [ ∵ D = 81 kg ]

Average weight of D, E, F and G = 75kg

⇒ Sum of weights of D, E, F and G = 75 × 4 = 300  

⇒ Sum of weights of E, F and G = 300 kg - 81kg = 219 kg

Now calculate sum of weights of 7 people by using above data

=  Sum of weights of A,B,C + Sum of weights of E,F,G + weight of D

= 211 kg + 219 kg + 81 kg = 511 kg

Average of weight of 7 people = 511 / 7 = 73 kg

Average weight of 7 people = 73  kg  

#SPJ2