Please help me understand these.

2. Compute the following sum of the arithmetic progression 2+4+6+-..+96 + 98 + 100 = 3. Write down a closed formula representing the geometric progression: 1 +3+32+33.+398 399 4. Is it true that n2 O(n3)? Circle the answer: yes no 5. Is it true that 10713 + 100n2 + 1000n + 10000 0(n25)? Circle the answer: yes no 6. Let (n) be the solution of the following recurrence T(n) +1. Give a function f(n) such that T(n) e(f(n)). f(n)