Question

Q. The mean weight of a group of 10 items is 29 and that of anther group of n items is 3. The mean of combined group of 10+n items is found to be 30. The value of n is
(a) 2
(b) 4
(c) 10
(d) 12​

Answer 1

10*29=290

n*3=3n

(290+3n)/(10+n)

30(10+n)=290+3n

300+30n=290+3n

300-290=30n-3n

27n=10

n=27/10

=2.7

i think this sum answer is it

mark me briliant if my answer is correct