Let A, B, C and D pay ₹ x, ₹ y, ₹ z and ₹ a.
According to the question,
x =
(y + z + a) ... (i)
y =
(x + z + a) ... (ii)
z =
(z + y + a) ... (iii)
Also, x + y + z + a = 60
Now, put the value of x + y + a = 4 z
Then, 4z + z = 60 ⇒ 5z = 60 ⇒ z = 12
Similarly, on putting the value of
x + z + a = 3y, we get
3 y + y = 60 ⇒ 4y = 60 ⇒ y = 15
Again, on putting the value of
y + z + a = 2x, we get
2x+ x = 60 ⇒ 3x = 60 ⇒ x = 20
N ow , x + y + z + a = 60
On putting the value of x, y and z, we get
12+ 15 + 20 + a = 60 ⇒ a = ₹ 13