If n + p = 6, and 3n - p = 4, then n - p is equal to:

Question: If n + p = 6, and 3n - p = 4, then n - p is equal to:

Solution:
Given that,
n + p = 6 ........(i)
3n - p = 4 ........(ii)

Adding equations (i) and (ii):
(n + p) + (3n - p) = 6 + 4
⇒ 4n = 10
⇒ n = 10/4
∴ n = 2.5

Putting the value of n in equation (i):
2.5 + p = 6
⇒ p = 6 - 2.5
∴ p = 3.5

Now, n - p = 2.5 - 3.5
= - 1