In the table, the sum of the numbers in each row, column and diagonal is the same. What is the value of P+Q+R+S?
The sum = 48 .... so.....
P + Q = 44
P + R = 38
P + S = 32
Q + S = 26
Q + R = 32
R + S = 20
Subtract the first two equations ⇒
Q - R = 6
Q + R = 32 add these
2Q = 38
Q = 19
S = 7
P = 25
R = 13
P + Q + R + S = 25 + 19 + 13 + 7 = 64
