In a class there are 60 students who belong to Nightingale, Peacock and Parrot house. There are four times as many students in Parrot house as Nightingale house; and six more in Peacock house than Nightingale house.

How many students are in each house?

ie x+4x+(x+6)=60

solving get x=9

hence nightingale=9

parrot=36

peacock 15

total=60