At a roller derby, 4 teams are competing. Each team is made up of 10 members, and each member needs a pair of roller skates to compete in and another pair of skates as a backup. None of the skates have laces yet, so each member is offered 3 sets of laces per pair of skates. How many sets of laces have been handed out?

How many team members are there? ** There are a total of 4 teams * 10 members per team =

<<4*10=40>>40 team members. How many pairs of skates does each person receive? ** Each person receives 1 pair of competing roller skates + 1 pair of backup roller skates = <<1+1=2>>2 pairs of roller skates. How many roller skates are there? ** So there are a total of 40 team members * 2 pairs of roller skates per team member = <<40*2=80>>80 roller skates. How many sets of laces have been handed out? ** There were therefore 80 roller skates * 3 sets of laces per pair of roller skates = <<80*3=240>>240 sets of laces handed out. #### 240 Bucky earns money each weekend catching and selling fish. He wants to save up for a new video game, which costs $60. Last weekend he earned $35. He can earn $5 from trout and $4 from blue-gill. He caught five fish this Sunday. If 60% were trout, and the rest were blue-gill, how much more does he need to save before he can buy the game? How much money does Bucky need to save? ** He is $25 short for the game because 60 - 35 = <<60-35=25>>25 How many trout did Bucky catch? ** He caught 3 trout because 5 x .6 = <<5*.6=3>>3 How many blue-gill did Bucky catch? ** He caught 2 blue-gill because 5 - 3 = <<5-3=2>>2 How much money did Bucky earn from the trout? ** He earned $15 from the trout because 3 x 5 = <<3*5=15>>15 How much money did Bucky earn from the blue-gill? ** He earned $8 from the blue-gill because 2 x 4 = <<2*4=8>>8 How much money did Bucky earn in total? ** He earned $23 total because 15 + 8 = <<15+8=23>>23 How much money is Bucky short? ** He is $2 short because 25 - 23 = <<25-23=2>>2 #### 2 Rylee is bored and decides to count the number of leaves falling off the tree in her backyard. 7 leaves fall in the first hour. For the second and third hour, the leaves fall at a rate of 4 per hour. What is the average number of leaves which fell per hour? How many leaves fell in the first hour? ** 7 leaves fell in the first hour. How many leaves fell in the second hour? ** 4 leaves fell in the second hour. How many leaves fell in the third hour? ** 4 leaves fell in the third hour. How many leaves fell during the 3 hours? ** The total number of leaves that fell during the 3 hours is 7 + 4 + 4 = <<7+4+4=15>>15 leaves. What is the average number of leaves which fell per hour? ** The average number of leaves that fell per hour is 15 leaves / 3 hours = <<15/3=5>>5 leaves per hour. #### 5 Libby is building an igloo in her backyard using bricks of snow. She builds her igloo in rows, using a total of 10 rows of bricks of snow. The bottom half of the igloo has 12 bricks of snow in each row while the top half of the igloo has 8 bricks of snow in each row. How many bricks of snow did Libby use for her igloo? How many rows are in the bottom half of the igloo? ** In the bottom half of the igloo, there are 10 rows / 2 = <<10/2=5>>5 rows of bricks of snow. How many bricks of snow are in the bottom half of the igloo? ** So in the bottom half of the igloo, there are 5 rows * 12 bricks of snow in each row = <<5*12=60>>60 bricks of snow. How many bricks of snow are in the top half of the igloo? ** In the top half of the igloo, there are 5 rows * 8 bricks of snow in each row = <<5*8=40>>40 bricks of snow. How many bricks of snow did Libby use for her igloo? ** There is therefore a total of 60 + 40 = <<60+40=100>>100 bricks of snow in the igloo. #### 100 In ten years, I'll be twice my brother's age. The sum of our ages will then be 45 years old. How old am I now? Define a variable ** Let X be my age now. How old will I be in ten years? ** In ten years, I'll be X+<<+10=10>>10 years old. How old will my brother be in ten years? ** In ten years, my brother will be (X+10)*1/2 years old. Write an equation ** In ten years, (X+10) + (X+10)*1/2 = 45. Simplify ** So (X+10)*3/2 = 45. Simplify ** X+10 = 45 * 2/3 = 30. Simplify ** X = 30 - 10 = <<30-10=20>>20 years old. #### 20 Haruto has tomato plants in his backyard. This year the plants grew 127 tomatoes. Birds had eaten 19 of the tomatoes. He picked the rest. If Haruto gave half of his tomatoes to his friend, how many tomatoes does he have left? How many tomatoes does Haruto have left? ** After the birds ate 19 of the tomatoes Haruto has 127 - 19 = <<127-19=108>>108 tomatoes left. How many tomatoes does Haruto have left? ** After giving half of his tomatoes to his friend, Haruto had 108 / 2 = <<108/2=54>>54 tomatoes. #### 54 When it rains, the three holes in the garage roof leak water at different rates. The largest hole leaks at a rate of 3 ounces of water per minute. The medium-sized hole leaks water at one-half the rate of the largest hole. And the smallest hole leaks water at a rate of one-third the rate of the medium-sized hole. When it rains, what is the combined amount of water, in ounces, that leak from all three holes over a 2-hour time period? How many ounces does the medium-sized hole leak? ** The medium-sized hole leaks at a rate of one-half that of the largest hole, or 3/2=<<3/2=1.5>>1.5 ounces per minute. How many ounces does the small-sized hole leak? ** The small-sized hole leaks at a rate of one-third that of the medium-sized hole, or 1.5/3=<<1.5/3=0.5>>0.5 ounces per minute. How many ounces does the combined holes leak? ** Combined, the three holes leak at a rate of 3+1.5+0.5=<<3+1.5+0.5=5>>5 ounces per minute. How many minutes are in two hours? ** Since one hour is 60 minutes, two hours is 2*60=<<2*60=120>>120 minutes. How many ounces of water will the three holes leak in total? ** In total, over the two hours, the three holes will leak a combined 120*5=<<120*5=600>>600 ounces of water. #### 600 Robin likes to bake cupcakes for friends and to make her puppy North happy. Once Robin ate four cupcakes with chocolate sauce and twice as many cupcakes with buttercream frosting on her own. How many cupcakes did Robin eat? How many buttercream cupcakes did Robin eat? ** Robin ate twice as many buttercream cupcakes as chocolate sauce cupcakes, or 2 * 4 = <<2*4=8>>8. How many cupcakes did Robin eat? ** So in total she ate 4 + 8 = <<4+8=12>>12 cupcakes. #### 12 Maddy's 4th grade class needs to make 1000 Valentine's Day cards to get a pizza party. There are 30 kids in the class. If everyone makes 8, how many more cards will they need to make to get a pizza party? How many cards will the kids make? ** If 30 kids each make 8 cards, they will have made 240 cards because 30*8 = <<30*8=240>>240. How many more cards will they need to make? ** Since 1000-240 = <<1000-240=760>>760, they need to make 760 more cards. #### 760 Harvey and his friend Sam decided to run a footrace in their school track field to see who was better at running. While at it, Harvey runs 8 miles more than his friend Sam, who runs a total of 12 miles. Calculate the total number of miles the two friends run together. How many miles did Harvey run? ** If Harvey ran 8 more miles, then he ran a total of 12 miles + 8 miles = <<12+8=20>>20 miles. How many miles did the two friends run together? ** The two friends ran a total of 20 miles + 12 miles = <<20+12=32>>32 miles #### 32