Problem Solving

A total of 30% of the geese included in a certain migration study were male. If some of the geese migrated during the study and 20% of the migrating were male, what was the ratio of te migration rate for the male geese to the migration rate for the female geese?

1)1/4
2)7/12
3)2/3
4)7/8
5)8/7

oa B

how i solved...
suppose 100 geese.
30 male and 70 female.

suppose 50 migrating.
10 male and 40 female.

ratio 1 to 4.

what went wrong?

The question asked is to calculate ratio of Migration rate of Male to Female.
ska7945, you are assumption is fine but you should calculate the rate.
As per your assumption -
rate of Male migration = 10/30 = 1/3
rate of female migration = 40/70 = 4/7

ratio of rate of male migration to female migration = (1/3)/(4/7)
= 7/12
Option B

@ carefreeamit
could you elaborate more on how you got the rate

Thanks in advance

mals24 wrote:@ carefreeamit
could you elaborate more on how you got the rate

Thanks in advance

suppose 100 geese.
30 male and 70 female.

suppose 50 migrating.
10 male and 40 female.

so 10 males migrated out of a total 30
and 40 females migrated of a total 70

therefore for males its 10/30 =1/3
females its 40/70 = 4/7

thus the ratio of males to females is

1/3/(4/7) which 7:12

hope that helps
do let me know if u have any doubts

It is an easy but tricky question.
May be it is safe, mostly, when we suspect from choice A if we got the number in first try.