Question

The mean of three numbers is 10. The mean of other four numbers is 12. Find the mean
of all numbers.
[HOTS, NCERT Exemplar]

please tell in simple way​

Answer 1

Answer:

Let the three numbers be a, b, c

Given that: a+b+c/3=10

a+b+c=30

Let the other four numbers be w, x, y, z

w+x+y+z/4=12

w+x+y+z=48

Required to find: mean of all nos.

so, (a+b+c)+(w+x+y+z)/7

=30+48/7

=77/7

=11

Therefore the mean of all numbers is 11. Hope it helps u