M can eat some scoops of ice-cream in 9 hours but with the help of N, the ice-cream gets finished in 5 hours. In how many hours can N alone eat the same number of ice-cream scoops?
1
11 hours
2
12 hours
3
13.5 hours
4
11.25 hours
M can eat some scoops of ice-cream in 9 hours but with the help of N, the ice-cream gets finished in 5 hours. In how many hours can N alone eat the same number of ice-cream scoops?