Laura is hosting a carwash. She will charge $5 for a car, $6 for a truck, and $7 for an SUV. They raised $100 in total. If they washed 5 SUVs and 5 trucks, how many cars did they wash?

How much did they earn from trucks? ** They earned $30 from trucks because 5 x 6 =

<<5*6=30>>30 How much did they earn from SUVs? ** They earned $35 from SUVs because 5 x 7 = <<5*7=35>>35 How much did they earn from cars? ** They earned $35 from cars because 100 - 35 - 30 = <<100-35-30=35>>35 How many cars did they wash? ** They washed 7 cars because 35 / 5 = <<35/5=7>>7 #### 7 There are 3 boxes of cereal. One box holds 14 ounces of cereal. Another box holds half the amount of the first box and 5 ounces less than the third box. How much cereal is there in all 3 cereal boxes? How much does the first box hold? ** First = <<14=14>>14 oz How much does the second box hold? ** Second = (1/2) * 14 = <<(1/2)*14=7>>7 oz How much does the third box hold? ** Third = 7 + 5 = <<7+5=12>>12 oz How much cereal is there in all 3 cereal boxes? ** 14 + 7 + 12 = <<14+7+12=33>>33 oz How much cereal is there in all 3 cereal boxes? ** There are 33 ounces of cereal in those 3 boxes. #### 33 Tom decides to get a new floor for his room. It cost $50 to remove the floor. The new floor costs $1.25 per square foot and Tom's room is 8*7 feet. How much did it cost to replace the floor? How many square feet is Tom's room? ** The room is 8*7=<<8*7=56>>56 square feet How much did the new carpet cost? ** So the new carpet cost 56*1.25=$<<56*1.25=70>>70 How much did it cost to replace the floor? ** So the total cost was 50+70=$<<50+70=120>>120 #### 120 Harry wants to build a homemade helium balloon with his son, Kevin, so he and Kevin go to the store with $200. They buy a giant sheet to turn into a balloon for $42, a rope for $18, and a propane tank and burner for $14. They plan to use the rest of the money on helium. The helium is $1.50 per ounce. For every ounce they buy, the balloon can fly 113 feet higher. How many feet up can they fly the balloon? How much money do they have left? ** They have $126 for helium because 200 - 42 - 18 - 14 = <<200-42-18-14=126>>126. How many ounces of helium can they buy? ** They can buy 84 ounces of helium because 126 / 1.5 = <<126/1.5=84>>84 How many feet up can they fly the balloon? ** They can fly 9,492 feet up because 84 x 113 = <<84*113=9492>>9,492 #### 9,492 John carves a giant marble rectangular prism 8 meters tall with a 2-meter square base. It has a density of 2700 kg per cubic meter. How much does it weigh? How many cubic meters is the statue? ** The marble statue has a volume of 2*2*8=<<2*2*8=32>>32 cubic meters How much does the statue weigh? ** So that means it has a weight of 2700*32=<<2700*32=86400>>86,400 kg #### 86,400 Vinny weighed 300 pounds then lost 20 pounds in the first month of his diet. He continued his diet but each month, he lost half as much weight as he had lost in the previous month. At the start of the fifth month of his diet, he worked harder to lose extra weight then decided to end his diet. If Vinny weighed 250.5 pounds at the end of his diet, how many pounds did he lose throughout the fifth month? How many pounds did Vinny lose in the second month? ** In the second month, Vinny lost half as much as he had the first month, so he lost 20 pounds / 2 = <<20/2=10>>10 pounds. How many pounds did Vinny lose in the third month? ** In the third month, he again lost half as much which was 10 pounds / 2 = <<10/2=5>>5 pounds. How many pounds did Vinny lose in the fourth month? ** And in the fourth month, he lost 5 pounds / 2 = <<5/2=2.5>>2.5 pounds. How many pounds did Vinny lose in the first four months? ** So in total, Vinny lost 20 + 10 + 5 + 2.5 = <<20+10+5+2.5=37.5>>37.5 pounds in the first four months. How many pounds did Vinny lose throughout the fifth month? ** Over his entire diet, he had lost 300 – 250.5 = <<300-250.5=49.5>>49.5 pounds. How many pounds did Vinny lose in the fifth month? ** So in the fifth month, Vinny must have lost 49.5 pounds total loss – 37.5 pounds loss in the first four months = 12 pounds. #### 12 A jet travels 580 miles in 2 hours. At this rate, how far could the jet fly in 10 hours? How far could the jet travel in one hour? ** In one hour the jet could travel 580 miles / 2 hours = <<580/2=290>>290 miles. How far could the jet fly in 10 hours? ** In 10 hours the jet could fly 290 miles * 10 = <<290*10=2900>>2900 miles. #### 2900 A singer is planning on releasing 3 songs in a month. If he worked on one song for 10 hours a day, and each song took 10 days to be completed, calculate the total number of hours he took to complete the 3 songs. How many hours does it take to complete one song? ** If he worked on a song for 10 hours a day, the total number of hours he takes to complete one song is 10*10 = <<10*10=100>>100 hours. How many hours did it take to complete the three songs? ** If one song took 100 hours to complete, the total number of hours the three songs took to be completed is 3*100 = <<3*100=300>>300 hours #### 300 Alice had 10 dozens of watermelons. She sold 40% of it yesterday and 1/4 of the remaining today, How many watermelons are left to be sold tomorrow? How many watermelons are there? ** Ten dozens of watermelons are equal to 10 x 12 = <<10*12=120>>120 watermelons. How many watermelons did Alice sell yesterday? ** Yesterday, Alice sold 120 x 40/100 = <<120*40/100=48>>48 watermelons. How many watermelons are left today? ** So, there are only 120 - 48 = <<120-48=72>>72 watermelons left for today. How many watermelons did Alice sell today? ** Today, Alice sold 72 x 1/4 = <<72*1/4=18>>18 watermelons. How many watermelons are left to be sold tomorrow? ** Hence, 72 - 18 = <<72-18=54>>54 watermelons are left to be sold tomorrow. #### 54 A spaceship is traveling to another planet. The spaceship travels at a consistent speed its entire journey unless it is stopped for the crew’s break. After launch, the spaceship traveled for 10 hours then stopped for 3 hours. It then traveled for another 10 hours then stopped for 1 hour. After this, the spaceship would take an hour’s break after every 11 hours of traveling and maintained this routine until the end of its journey. If the entire journey took 3 days then how long, in hours, was the spaceship not moving? How many hours did the spaceship travel on the first day? ** On the first day, the spaceship spent a total of 10 hours + 10 hours = <<10+10=20>>20 hours traveling. How many hours did the spaceship not move on the first day? ** On the first day, the spaceship spent a total of 3 hours + 1 hour = <<3+1=4>>4 hours not moving. How many hours did the spaceship travel and not move on the first day? ** This is a total of 20 hours traveling + 4 hours not moving = <<20+4=24>>24 hours or 1 day. How many days did the rest of the journey take? ** So the rest of the journey took place over 3 days journey – 1 first day = <<3-1=2>>2 days. How many hours did the rest of the journey take? ** This is the same as 2 days * 24 hours = <<2*24=48>>48 hours. How many hours are in the spaceship’s 12 hour blocks? ** In these 2 days, the spaceship’s time is split into 11 hours traveling + 1 hour break = <<11+1=12>>12 hour blocks. How many hours was the spaceship not moving in the last 2 days? ** So in the last 2 days, the spaceship wasn't moving for a total of 48 hours / 12 hour blocks = <<48/12=4>>4 hours. How many hours was the spaceship not moving in total? ** Adding this to breaks from the first day shows that the spaceship was not moving for a total of 4 + 4 = <<4+4=8>>8 hours. #### 8