Question

Thirty percent of people in a sports club are female there are 245 male how many female are there

Answer 1

245/x = 70/100 
cross multiply to get 70x = 24500, divide both sides by 70 to get x = 350. 
There are 350 people in the club total, and 245 are male, so you can subtract to get 350 - 245 = 105 female.