total seats spread is 728
no of rows is 28
i.e 28 rows will give 728 seat spreads
1 row will give x seat spread
28------- 728
1--------- x
cross multiplication
728 x 1 = 28 * x
728 = 28x
divide both sides by 28
728 / 28 = 28x/28
x = 26 seat spreads
1 row will give 26 seat spreads
for 12 rows we have 12 x 26
= 312 seats spread
12 rows will accommodate 312 seats
