The combination is .
The combinations formula is .
(Apply combinations formula)
()
The total number of combinations are 10.
![\"\"](\"/userfiles/image/steps_images/step1.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=c2a9ef7365702ba971f281f0ee04916e.png\")
.![\"\"](\"plugins/fckeditor_wiris/integration/showimage.php?formula=8d75289d80f901b8d2988dbf1d5d3b6a.png\")
.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=4cfb8a8989fc5c317330eaa865386d10.png\")
(Apply combinations formula)![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=a54bbf0da56a2549a88fb0cf84f72162.png\")
(![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=f4a62cc82e7915521afa40f62a5394f5.png\")
)![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=53ffb4e1bbe34290b5e8776b5a7b4105.png\")
(![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=b6e0ec4ddae757bdad177b163998ed9d.png\")
)![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=e2623c8a2ee8e5a781523f37c391baa3.png\")
![\"\"](\"/userfiles/image/steps_images/solution.JPG\")