The sum of three numbers $a, b$ and $c$ is $60$. If we decrease $a$ by $1$, we get the value $N$. If we increase $b$ by $2$, we get the value $N$. If we multiply $c$ by $3$, we also get the value $N$. What is the value of $N$?
a + b + c = 60
(a - 1) = N → a = N + 1
(b + 2) = N → b = N - 2
3c = N → c = N / 3
(N + 1) + (N - 2) + N / 3 = 60
(7/3)N = 61
N = (61 * 3) / 7 = 183 / 7
N = 26.14
+-487 
