a cat and a mouse together weigh 10kg
a dog and a mouse together weigh 20kg
a dog and a cat together wiegh 24kg
HOW MANY KGS DO THEY ALL WEIGH TOGETHER?
Weight of cat and mouse = 10kg
so C + M = 10 kg (i)
similarly D + M = 20kg(ii)
and D + C = 24kg(iii)
adding (i) ,(ii) and (iii) we get
C + C + D + D + M + M = 10 + 20 + 24 = 54kg
so 2C+2D+2M = 54 kg
taking 2 as common
so 2(C+D+M) = 54kg
so (C+D+M) = 54/2 = 27kg
so cat,mouse and dog together weigh 27 kg.