Ian won $100 in the lottery. He decided to use the money to pay off debts. He paid $20 to Colin. He then paid twice as much to Helen, as he had paid to Colin. Then finally, he paid half as much to Benedict, as he had paid to Helen. How much money, in dollars, does he have left after paying off debts?

How much money did Ian have after paying Colin? ** Starting with $100, he paid $20 to Colin, leaving him with $100-$20=$

<<100-20=80>>80. How much money did Ian pay to Helen? ** Twice as much as $20 is 2*$20=$<<2*20=40>>40. How much money did Ian have after paying Helen? ** Thus, he paid $40 to Helen, leaving him with $80-$40=$<<80-40=40>>40. How much money did Ian pay to Benedict? ** Half as much to Benedict as he had paid to Helen is $40/2=$<<40/2=20>>20. How much money does Ian have left after paying off debts? ** Thus, he paid $20 to Benedict, leaving him with $40-$20=$20 after paying off all debts. #### 20 A company has 200 employees. 60% of the employees drive to work. Of the employees who don't drive to work, half take public transportation. How many more employees drive to work than take public transportation? How many employees drive to work? ** Drive to work:200(.60)=<<200*.60=120>>120 How many employees don't drive to work? ** Don't Drive to work:200-120=<<200-120=80>>80 How many employees take public transportation? ** Public Transportation:80(.50)=40 employees How many more employees drive to work than take public transportation? ** 80-40=<<80-40=40>>40 employees #### 40 Jan buys 1000 feet of cable. She splits it up into 25-foot sections. She gives 1/4 of that to a friend. She then puts half of the rest in storage. How much does she keep on hand? How many sections does she get? ** She gets 1000/25=<<1000/25=40>>40 sections How many sections does she give away? ** She gives away 40/4=<<40/4=10>>10 sections How many sections does she keep? ** So she keeps 40-10=<<40-10=30>>30 sections How many sections does she keep on hand? ** She keeps 30/2=<<30/2=15>>15 sections on hand #### 15 Emery and Serena go to their school library, and each borrows a copy of The life of Jack Steve's book to read for their school project. If Emery can read five times as fast as Serena, and the book takes her 20 days to read, what's the average number of days the two take to read the book? How many days did Serena take to read the book? ** If Emery took twenty days to read the book, then it took Serena 5*20 = <<20*5=100>>100 days to read the whole book. How many days did the two take to read the book? ** The total number of days taken by the two to read the book is 100+20 = <<100+20=120>>120 days. What's the average number of days the two take to read the book? ** The average number of days the two take to read the book is 120/2 = <<120/2=60>>60 days. #### 60 A laboratory has 22 beakers of liquid in a fume hood, and 8 of the beakers have copper ions in them. Adding three drops of a solution will turn the liquid in a beaker blue if there are copper ions present. If the beakers are tested one by one for copper ions and 45 drops are used before all 8 beakers with copper ions are found, how many beakers without copper ions were tested? How many beakers were tested? ** There were 45 / 3 = <<45/3=15>>15 beakers tested to find all the beakers with copper ions. How many beakers without copper ions were tested? ** Thus, 15 - 8 = <<15-8=7>>7 beakers without copper ions were tested. #### 7 Jolene and Phil have four children, each with the same birthday. They gave birth to their first child exactly 15 years ago. They gave birth to their second child exactly one year after the birth of their first child. They gave birth to their third child on the fourth birthday of their second child. Two years after the birth of their third child, they gave birth to their fourth child. How old, in years, is their fourth child? How old is their first child? ** Their 1st child was born 15 years ago, and therefore is <<15=15>>15 years old. How old is their second child? ** Their 2nd child was born 1 year after their 15-year-old child, and therefore is 15-1=<<15-1=14>>14 years old. How old is their third child? ** Their 3rd child was born 4 years after their 14-year-old child, and therefore is 14-4=10 years old. How old is their fourth child? ** Their 4th child was born 2 years after their 10-year-old child, and therefore is 10-2=8 years old. #### 8 Bryan starts exercising at home during quarantine. To start, he decides to do 3 sets of 15 push-ups each. Near the end of the third set, he gets tired and does 5 fewer push-ups. How many push-ups did he do in total? How many push-ups did Bryan do in total? ** In total, Bryan would have done 3 sets * 15 push-ups/set = <<3*15=45>>45 push-ups. How many push-ups did Bryan do in total? ** Subtracting the push-ups he didn't do in the third set, Bryan did 45 push-ups - 5 push-ups = <<45-5=40>>40 push-ups. #### 40 Mark buys a loaf of bread for $4.20 and some cheese for $2.05. He gives the cashier $7.00. If the cashier only has 1 quarter and 1 dime in his till, plus a bunch of nickels, how many nickels does Mark get in his change? How much does Mark give the cashier? ** First subtract the cost of Mark's groceries from the amount he gives the cashier to find how much he gets in change: $7.00 - $4.20 - $2.05 = $<<7-4.2-2.05=0.75>>0.75 How much does Mark get paid in nickels? ** Then subtract the value of a quarter in cents (25) and the value of a dime in cents (10) from the change amount to find how much Mark gets paid in nickels: $0.75 - $0.25 - $0.10 = $<<0.75-0.25-0.10=0.40>>0.40 How many nickels does Mark get? ** Now divide the amount Mark gets in nickels by the value per nickel in cents (5) to find how many nickels Mark gets: $0.40 / $0.05/nickel = <<0.40/0.05=8>>8 nickels #### 8 Max likes to collect model trains. He asks for one for every birthday of his, and asks for two each Christmas. Max always gets the gifts he asks for, and asks for these same gifts every year for 5 years. At the end of the 5 years, his parents give him double the number of trains he already has. How many trains does Max have now? How many trains does Max get each year? ** Max gets 1+2=<<1+2=3>>3 trains per year. How many trains does Max get in total? ** He repeats this for 5 years, meaning he gets 5*3 =<<5*3=15>>15 trains. How many trains does Max get from his parents? ** When this number is doubled by his parents, it becomes 15*2= <<15*2=30>>30 trains. How many trains does Max have now? ** Since he already had 15 model trains, his total becomes 15+30= <<15+30=45>>45 trains. #### 45 Jake has $5000. He spends $2800 on a new motorcycle, and then spends half of what's left on a concert ticket. Jake then loses a fourth of what he has left. How much money does he have left? How much does Jake have left after buying a new motorcycle? ** Jake has 5000-2800 = $<<5000-2800=2200>>2200 left How much does Jake have left after buying a concert ticket? ** Jake has 2200/2 = $<<2200/2=1100>>1100 How much does Jake lose? ** Jake loses 1100/4 = $<<1100/4=275>>275 How much money does he have left? ** Jake has 1100-275 = $<<1100-275=825>>825 left. #### 825