A shopkeeper sells two qualities of rice at the rates of $44 per kg. and $54 per kg, gaining 10% and 20% profit respectively. If he mixes the two variants in the ratio 2:3 and sells the mixture at $55.9 per kg., what is his gain or loss?

Rivera and Jose together can do a work in 30 hours, but if Maximiliano also helps them they can finish it in 5 hours only. How long would it take if Maximiliano has to do it alone?