Probability

In a school , 1 - 25% = 75% of students not eating fish.
Among those not eating fish, 1 - 12.5% = 87.5% are female students.
So in a school ,
(75%)(87.5%) = 65.625% students are female not eating fish.
Since 1 - 20% = 80% of its female students not eating fish ,
so there are 65.625% / 80% = 82.03125% female students in a school.
So P(E) = 0.8203125 = 0.8203 (4 dec.)

Assume following:
Male = M who eat fish = Ma, don't = Mb (M=Ma+Mb)
Female = F, ... Fa... Fb (F = Fa + Fb)
Total amount of population = x.... xa...xb (x = xa+xb)
Ma+Fa = xa ... Mb+Fb = xb



Question given:
25%x = xa

20%F = Fa (-->80%F = Fb)

Mb = 12.5%xb

Question request = Find % of F from x
25%x = xa = Ma + Fa


75%x = xb = Mb + Fb


Mb = 12.5%xb
xb = 8Mb
Fb = 7Mb
1/7Fb = Mb

25%x = xa = Ma + Fa =


75%x = xb = Mb + Fb = 1/7Fb+Fb = 8/7Fb

75%x = 8/7Fb
75%x = 8/7 (80%F)

0.8203125 x = F...


If you don't want algebraic method, just consider the above part is just proving my method
In the answer, just write
Female =( 75%(1) x 7/8 ) / 80%

It is actually meaningless (except for examination requirement) to say that Algebraic method is non-acceptable.

Algebraic method is just a method for easy solving steps.
Final answer must be the same after adjusting the positions