Question

28. The average weight of 20 students of a class is
33 kg. If the average weight of all the boys is 35 kg
and the average weight of all the eight girls is ykg
then find y.
(b) 29
(c) 30
(d) 31
Maths

Answer 1

Answer:

Correct option is

B

13 and 27

Let x be the number of boys and y be the number of girls

⇒23.25×(x+y)=30x+20y

⇒23.25x+23.25y=30x+20y

⇒23.25x−30x=20y−23.25y

⇒−6.75x=−3.25y

⇒6.75x=3.25y

⇒

y

x

=

6.75

3.25

=

6.75×100

3.25×100

=

675

325

=

27

13

∴the possible strength of boys and girls respectively in the same class are 13 and 27

Answer 2

The correct ans is b part