Question

pls explain the sum
ans : d

Answer 1

Let the population be 'x'.
Given that 60% of population are males.
Thereflre no.of males=60/100×x=3x/5
and no.of females=40/100×x=2x/5
given that a% of males are educated and b% of females are educated.
Therefore educated males=a/100×3x/5
=3ax/500
and educated females=b/100×2x/5
=2bx/500
Then,
no.of uneducated males=3x/5-3ax/500
=(300x-3ax)/500 no.of uneducated females=2x/5-2bx/500
=(200x-2bx)/500
As per given condition we get,
educated males+uneducated females=educated females+uneducated males
3ax/500+(200x-2bx)/500=2bx/500+. (300x-3ax)/500
3ax+200x-2bx=300x-3ax+2bx
6ax-4bx=50x
3a-2b=50
Now by traial and error method we should find our answer.
As options are given we need to substitute each pair in the above equation,the pair which satisfies the equation is the answer.

Here pair of value which is in option D satisfies the equation.
That is (30,20) is the answer.




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