As we know that 13.25 yards = 6.99
We can use our knowledge to figure out the price of one yard by dividing both sides by 13.25:
13.25yards = 6.99
1yard = 699/1325
Then multiply both sides by 24 to get the price for 24 yards:
24yards = 12.6611321
As we are dealing with money we will only take the first two decimal points and NOT round:
24 yards would cost $12.66