Answer the questions based on the following information.
A, B, C and D collected one-rupee coins following the given pattern.
Together they collected 100 coins. Each one of them collected even number of coins.
Each one of them collected at least 10 coins. No two of them collected the same number of coins.
The maximum number of coins collected by any one of them cannot exceed
The relationship between two variables \( x \) and \( y \) is given by \( x + py + q = 0 \) and is shown in the figure. Find the values of \( p \) and \( q \). Note: The figure shown is representative.