1 
P1  Potentiometers 
UVA 

2 
P2  Pashmak and Parmida's problem 
Codeforces 
Codeforces Round #261 (Div. 2) 
3 
P3  Interval Product 
UVA 

4 
P4  Interesting Array 
Codeforces 
Codeforces Round #275 (Div. 1) & Codeforces Round #275 (Div. 2) 
5 
P5  Last Chance 
Codeforces 
Codeforces Beta Round #98 (Div. 2) 
6 
P6  Xenia and Bit Operations 
Codeforces 
Codeforces Round #197 (Div. 2) 
7 
P7  Queue 
Codeforces 
Codeforces Beta Round #75 (Div. 1 Only) & Codeforces Beta Round #75 (Div. 2 Only) 
8 
P8  Sereja and Brackets 
Codeforces 
Codeforces Round #223 (Div. 1) & Codeforces Round #223 (Div. 2) 
9 
P9  Babaei and Birthday Cake 
Codeforces 
Codeforces Round #343 (Div. 2) 