Question 515123
In the question how many brothers and sister you have the brother has answered "i have as many sisters as brothers" in the other hand the sister answers "i have twice more brothers than sisters". How many brothers and sisters are they?
======================
Let B = the total number of brothers
Let S = the total number of sisters
When the brother is asked, he doesn't count himself so we can write:
B - 1 = S [same number of brothers and sisters]
When the sister is asked, likewise she doesn't count herself, so we have:
2(S - 1) = B [twice as many brothers as sisters]
Solve for B in the 1st equation and substitute into the 2nd:
2(S - 1) = S + 1
This gives S = 3
So there are 3 sisters and 4 brothers