Can you walk me through the solution of: As Sally walked to school, she was holding the strings to 25 red balloons, 7 green balloons, and 12 yellow balloons. Suddenly, a gust of wind caused 40% of the red balloons to burst.  The shockingly loud sound startled Sally, and she accidentally released half of the yellow balloons.  But as she neared the school grounds, she found 8 blue balloons caught in a tree, and she added 75% of them to her remaining clutch of balloons, which she carried into the school.  What number of balloons did she finally carry into the school?