tabsang wrote:

The average scores in two classes A and B in a particular test are 60 and 75 respectively. What is the average score of the two classes taken together?

(1) The number of students in class A is 50% more than the number of students in class B.

(2) The number of students in the two classes A and B are in the ratio of 3:2

Cheers,

Taz

Let number of students in class A be "a" and number of students in class B be "b"

Combined average = (60*a + 75*b)/ (a + b)

= (60*(a/b) + 75)/( 1 + (a/b))

So, if we know the ratio of number of students in class A and B then we can find the answer

STAT1

The number of students in class A is 50% more than the number of students in class B.

=> a = 1.50 * b

=> a/b = 1.5

SUFFICIENT!

STAT2

The number of students in the two classes A and B are in the ratio of 3:2

=> a/b = 3:2 = 1.5

SUFFICIENT!

Hence, Answer will be D

Hope it helps!

_________________

ankit

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