Question
Question: The no. of negative integral solutions of equation x + y + z + w + 20 = 0 is:...
The no. of negative integral solutions of equation x + y + z + w + 20 = 0 is:
A
23C3
B
40C3
C
19C3
D
24C3
Answer
19C3
Explanation
Solution
Let x = -a, y = -b, z = -c, w = -d.
∴ - a - b - c - d + 20 = 0.
a + b + c + d = 20.
No. of solutions = 19C3.