Uhhh 18?? 9+9, 10+8, 7+11, 6+12, 5+13, 4+14, 3+15, 2+16, 1+17
Well I would change it to feet to make it easier. There are 12 I inches in a foot so I would divide by 12. 3,600÷12=300 so the playground would be 300feet long. Which is easier than 3,600 inches. ANSWER:300 feet
If that 25/4 is a fraction them the answer is 53/4. Or in simplest form 3 5/16 or 3.3125