Question

(18. A test was conducted in three sections X, Y and Z of
tenth class. The average marks per student of
sections X and Y together is 66. The average marks
per student of sections Y and Z together is 63. The
average marks per student of sections Z and X
together is 67. The average marks per student of the
three sections together is A. Find the number of
integral values that A can take.​

Answer 1

Step-by-step explanation:

According to question

(i) x+y83x+76y=79

⇒x=43y

(ii) y+z76y+85z=81

Z=45y

Average of all 3=x+y+z83x+76y+85z

=43y+y+45y83(43y)+76y+854(85)

⇒43+1+454249+76+4425

=43+4+54249+304+425