Question Number 104972 by 1549442205PVT last updated on 25/Jul/20

In the a sport camp, 65% children know playing the football,70%−in voleyball,75%−in basketball.What is least number of children who know playing all above three sport games? (Answer 10%)

Answered by mr W last updated on 25/Jul/20

simple way without using set theory: N_F =children playing football only N_(F,V) =children playing both football and volleyball N_(F,V,B) =children playing all three sports N_F +N_(F,V) +N_(F,B) +N_(F,V,B) =65 ...(i) N_V +N_(F,V) +N_(V,B) +N_(F,V,B) =70 ...(ii) N_B +N_(F,B) +N_(V,B) +N_(F,V,B) =75 ...(iii) i+ii+iii: N_(F,V,B) +2(N_F +N_V +N_B +N_(F,V) +N_(F,B) +N_(V,B) +N_(F,V,B) )−(N_F +N_V +N_B )=210 N_(F,V,B) +2×100−(N_F +N_V +N_B )=210 N_(F,V,B) =10+(N_F +N_V +N_B ) N_(F,V,B) ≥10 i.e. at least 10% children know playing all three sport games.

Commented by1549442205PVT last updated on 25/Jul/20

Great!Thank you Sir!

Commented byRasheed.Sindhi last updated on 25/Jul/20

Superb! Elegant! MrW Sir!