A is the average marks of a group of 10 students in a class and A+8 is the average of a group of 15 students which includes the group of 10 students as given. The total marks obtained by the group of 10 students is X and the total marks obtained by the group of 15 students is Y. If X : Y = 3 : 5, then the value of A+X+Y is _________.
Answer & explanation
Correct answer: option 4
Sum of marks of 10 students = 10A
Sum of marks of 15 students = 15 × ( A + 8) = 15A + 120
ATQ ,
\(\frac{10A}{15A + 120}\) = \(\frac{3}{5}\)
45A + 360 = 50A
5A = 360 ⇒ A = 72
SO , A + X + Y = 72 + 720 + 1080 + 120 = 1992