Darren wins a coupon for four dollars off lunch specials for each of five days. He pays $75 for his five lunch specials.

To find out how much Darren pays for each lunch special without the coupon, we subtract the coupon amount from the cost of each lunch special: $75 / 5 = $<<75/5=15>>15.

Thus, each lunch special costs $15 without the coupon, and with the coupon, each lunch special costs $15 - $4 = $<<15-4=11>>11. Answer: \boxed{11}.

To solve this problem, let's break it down step by step:

Step 1: Determine the value of each coupon.
Darren wins a coupon for four dollars off lunch specials for each of the five days. So, the value of each coupon is $4.

Step 2: Calculate the total amount saved with the coupons.
Since Darren has five coupons and each coupon is worth $4, he saves a total of 5 * $4 = $20.

Step 3: Calculate the total cost of the lunch specials without considering the coupons.
Darren pays $75 for his five lunch specials without considering the coupons.

Step 4: Subtract the amount saved with coupons from the total cost of lunch specials.
By subtracting $20 (the amount saved with coupons) from $75 (the total cost of lunch specials without coupons), we get $75 - $20 = $55.

Step 5: Determine the cost of each lunch special.
Now, divide the total cost ($55) by the number of lunch specials (5) to find the cost of each lunch special.
$55 ÷ 5 = $11.

Therefore, the cost of each lunch special without the coupon is $11.