Question

P + P + O = 14 N + N + M = 20 O + M + P = 12 P + M + N = 18 Find O.

Answer 1

Given, 
P+P+O = 14  ⇒ 2P+O=14 ⇒ O=14-2P ---------- 1
N+N+M = 20 ⇒ 2N+M=20 ⇒ M=20-2N ---------- 2
O+M+P = 12 ------- 3
P+M+N = 18 ------- 4

1 in 3
14-2P+M+P = 12
M-P = 12-14
M-P = -2
P = M+2 ----------- 5

2 in 4
P+20-2N+N = 18
P-N = 18-20
P-N = -2
P = N-2  --------- 6

Equating P values, we get M+2=N-2 ⇒ N = M+4 in 2
M = 20-2M-8
3M=12
M=4
So, N= M+4 = 4+4 = 8

M,N values in 4
P+4+8 = 18
P+12 = 18 ⇒ P = 18-12
P = 6

Placing M, P values in 3
O+4+6 = 12
O = 12-10
O = 2 is the answer

Answer 2

find the answer please !