other Maths Puzzle Numerical Ability

Consider three classes A, B and C with 20, 30 and 50 students respectively. The averages score in maths of students in class B is 16 more than that of those in class C and the average score of those in class A is 2 more than the overall average of scores in A, B and C. What is the difference between average of class C and class A?

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avg in class c=x
avg in class b=x+16
avg in class a=y
now acc to the condition given the overall avg of all classes={20y+30(x+16)+50x}/100
then acc to condition in last statement,
y={{20y+30(x+16)+50x}/100}+2
(y-2)100=20y+30x+480+50x
100y-200=80x+20y+480
80y-80x=680
y-x=8.5

ANS=8.5
10 years agoHelpfull: Yes(1) No(0)

other Other Question

Sum of first 25 terms in AP is 525, sum of the next 25 terms is 725, what is the common difference? All algorithms discussed in this chapter for determining the minimum spanning tree

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