The entire budget of Centerville is $3000 / 0.15 = $<<3000/0.15=20000>>20,000
The budget for the parks is $20,000 * 0.24 =$<<20000*0.24=4800>>4,800
After the park and the library there will be $20,000 - ($3,000 + $4,800) = $<<20000-(3000+4800)=12200>>12,200 left in the budget.
#### 12,200