Three of the five positive integers p, q, r, s, t are even and two of them are odd (not necessarily in order). Consider the following :

1. p + q + r - s - t is definitely even.

2. 2p + q + 2r - 2s + t is definitely odd.

Which of the above statements is/are correct?

If p, q, r and s are distinct single digit positive numbers, then what is the greatest value of (p + q) (r + s)?

Each digit of a 9-digit number is 1. It is multiplied by itself. What is the sum of the digits of the resulting number?

Let pp, qq and rr be 2-digit numbers where p < q < r. If pp + qq + rr = tt0, where tt0 is a 3-digit number ending with zero, consider the following statements :

1. The number of possible values of p is 5.

2. The number of possible values of q is 6.

Which of the above statements is/are correct?