1. In January the worth of a stock decreased by 40% and in February it increased by 50%, What is the net percentage change in the worth of the stock in the two-month period?
2. On a test, the average score of 12 boys in a class is 92 and the average score of 8 girls in the class is 96. What is the average score of the entire class?
1 x = stock price
40% decrease leaves 60% value = .6x
then a 50% increase .6x * 1.5 = .9x .9 means the stock is worth 90% of its original price (10 decrease from original price)