Problem Solving

the average age of 600 students of a class is 10.75; by enrolment of 40 new students , the average age is lowered to 10.4375 years. find the average age of the new students.

5.6

R.k91 wrote:the average age of 600 students of a class is 10.75; by enrolment of 40 new students , the average age is lowered to 10.4375 years. find the average age of the new students.

Hi!

Is this a GRE question? There are no entry questions on the GMAT.

The first thing to note is that, on the GRE, you actually have access to a calculator. While you don't need to use it (in fact it's often quicker to solve multiple choice questions without a calculator), on the numeric entry questions the calculator can be a very valuable tool.

If you have access to a calculator, you can simply apply the average formula twice (as Anurag did) without all of fancy simplification (which is way beyond the scope of a non-calculator standardized test).

Please always cite the source of your questions!

Is this not too calculation intensive.
[16*(10.4375) - 15*(10.75)]
Can't we approximate it to
16*10.4-15*10.7
=166.4-162.0
=4.4(approx)
I know approx is no way near to real thing...
but in actual exam that's what I would have done

1947 wrote:Is this not too calculation intensive.
[16*(10.4375) - 15*(10.75)]
Can't we approximate it to
16*10.4-15*10.7
=166.4-162.0
=4.4(approx)
I know approx is no way near to real thing...
but in actual exam that's what I would have done

Hi!

If it's actually a numeric entry question, then you have to enter the answer on the computer - it's not multiple choice.

Again, these questions do NOT appear on the GMAT.