1/5 of 300 is 60
2) There were 20 questions on the test. Joe got 3 wrong. What percent did he get correct? _________
Each question is worth 100/20 or 5 points, so he got 85% correct.
3) What is 80% of 80% of 125?
4/5 * 4/5 * 125 = 20
4) What percent of 50 is 20? _______________
20/50 * 100 = 40, so 40%
5) 7 is 70% of what number? ______
7/x = 70/100, so x = 10
6) You are a helper an expedition that finds $10 million in pirate treasure. The leader has stated that he gets 80% and the rest will be split among the 10 helpers (of which you are one). What is your cut of the loot? _________________
10m - 8m = 2m, 2,000,000 / 10 = $200,000
7) If Sabrina earns $150 a day, and her boss just increased her salary to $180 a day, by what percentage was her salary increased? ________________
30/150 = .2, so 20%
8) Duncan sold 50% of his DVDs plus 1/2 a DVD to Veronica. He then sold 50% of what was left plus half a DVD to Pat. He has five DVDs left. How many DVDs did he have originally? _____
Work backwards. 5 => 11 => 23 DVDs
9) If you flipped a set of 2 pennies 1000 times, what percentage of times would you expect both pennies to come up heads? _________________
TT, TH, HT, HH are the only 4 possibilitys on each try, so 25% likely that you will get HH.
10) If you put $100 in the bank, and it earns 50% interest each year, estimate how much will you have after 6 years. (Keep in mind that the interest is compounded each year) _____________
After the first your you have $150, after the secon year you will have $225
3rd year) $337.5
4rth year) $506
5th year) $759
and finally have 6 years, you have $1,139