Question

their are 3 cats of different weight. first and second cats weigh 7kg altogether. second and third weigh 8kg altogether. first and third weigh 11th altogether. what is the weight of each cat

Answer 1

let the weight of first cat be x
second cant be y
third cat be z
there fore2(x+y+z)=11+7+8
x+y+z=13
x+y=7
7+z=13
z=6
y+z=8
6+y=8
y=2
x+2=7
x=5
x,y,z=5,2,6

Answer 2

Let the weight of 1st, 2nd and 3rd cat be x, y, z respectively.

According to the question --
 x + y = 7 => x = 7 - y
y + z = 8  ...........(i)
x + z = 11 ...........(ii)

Now putting the value of x in (ii),
 7 - y + z = 11
 - y + z = 4 ..........(iii)

Now subtracting (iii) from (ii) we get,
z = 6 kg
Now putting the value of z in (iii),
 - y = 4 - 6
y = 2 kg

x = 7 - 2 = 5kg

So weight of 1st cat = 5 kg, 2nd cat = 2kg, 3rd cat = 6kg