#### Answer

Option 2 : 17.6 pounds for 18.69 dollars is the best buy.

#### Work Step by Step

1. 35.2 pounds for 36.96 Dollars
First we try to put the detail in ratio as $\frac{35.2 pounds}{36.96 Dollars}$
Now we have a coupon of 1 dollar for transaction above 8 pounds.
So, $\frac{35.2 pounds}{35.96 Dollars}$ (36.96 - 1 = 35.96)
$\approx \frac{0.98 pounds}{1 Dollars}$
2. 17.6 pounds for 18.69 Dollars
First we try to put the detail in ratio as $\frac{17.6 pounds}{18.69 Dollars}$
Now we have a coupon of 1 dollar for transaction above 8 pounds.
So, $\frac{17.6 pounds}{17.69 Dollars}$ (18.69 - 1 = 17.69)
$\approx \frac{0.99 pounds}{1 Dollars}$
3. 3.5 pounds for 4.25 Dollars
First we try to put the detail in ratio as $\frac{3.5 pounds}{4.25 Dollars}$
$\approx \frac{0.82 pounds}{1 Dollars}$
So compairing All three options option 2. 17.6 pounds for 18.69 dollars is the best buy.