From the given responses, find the missing number.

$7$	$9$	$5$	$11$
$4$	$15$	$12$	$7$
$13$	$8$	$11$	$?$

Read the following information carefully and answer the question given below-

In each of the following questions, select a figure from amongst the four alternatives, which when placed in the blank space of figure (X) would complete the pattern.

Which answer figure will complete the pattern in the question figure?

Identify the figure that completes the pattern.

  Select a figure from amongst the Answer Figures which will continue the same series as established by the four Problem Figures.

Identify the missing figure to complete the matrix. 

Select a suitable figure from the four alternatives that would complete the figure matrix.

Select a figure from amongst the Answer figures which will continue the sequence of series established by the Problem Figures.

Group the given figures in to three classes using each figure only once.