A mad scientist created a shrink ray device that, when used on anything, would cause it to shrink by 50%. The scientist, eager to use his new invention, looked through his house for something to shrink zap. The first thing he found and zapped was his wife, who at the time was carrying a tray containing 5 cups filled with coffee. If each coffee cup held 8 ounces of fluid before being zapped, how many ounces of coffee remained after his wife and the cups filled with coffee were shrink zapped?

Before the zap, the wife held 5 cups, each with 8 ounces of coffee, for a total of 5*8=

<<5*8=40>>40 ounces of coffee. After the zap, the coffee cups and their contents were shrunk by 50%, for a total of 0.5*40=<<0.5*40=20>>20 ounces of coffee. #### 20 A building has 20 floors. Each floor is 3 meters high, except for the last two floors. The last two floors are each 0.5 meters higher. How tall is the building? There are 20 - 2 = <<20-2=18>>18 floors that are each 3 meters high. So the first 18 floors is 18 x 3 = <<18*3=54>>54 meters high. The last two floors are each 3 + 0.5 = <<3+0.5=3.5>>3.5 meters high. So the total height of the last two floors is 3.5 x 2 = <<3.5*2=7>>7 meters. Therefore, the building is 54 + 7 = <<54+7=61>>61 meters high. #### 61 A school canteen sells a sandwich at $2, a hamburger at $2, one stick of hotdog at $1, and a can of fruit juice at $2 each can. Selene buys three sandwiches and a can of fruit juice. Tanya buys two hamburgers and two cans of fruit juice. How much do Selene and Tanya spend together? Three sandwiches cost 3 x $2 = $<<3*2=6>>6. So, Selene spends $6 + $2 = $<<6+2=8>>8. Two hamburgers cost 2 x $2 = $<<2*2=4>>4. Two cans of fruit juice cost 2 x $2 = $<<2*2=4>>4. Thus, Tanyah spends $4 +$4 = $<<4+4=8>>8. Therefore, Selene and Tanya spend $8 + $8 = $<<8+8=16>>16. #### 16 Julia had to make 6 cakes for the party. Each cake takes 12 minutes to mix and needs 9 more minutes to bake than mix. Then it takes 6 more minutes to cool and decorate than to bake. How many hours will it take to make all 6 cakes? It takes 12 + 9 =<<12+9=21>>21 minutes to bake each cake. It takes 21 + 6 = <<21+6=27>>27 minutes to cool and decorate each cake. Therefore, it takes a total of 12 + 21 + 27 = <<12+21+27=60>>60 minutes to make one cake. Thus, it takes 60/60 = <<60/60=1>>1 hour to bake one cake. So, it will take 1 x 6 = <<6=6>>6 hours to bake all 6 cakes. #### 6 Salaria is growing oranges this summer. She bought two types of trees. She has 50% of tree A and 50% of tree B. Tree A gives her 10 oranges a month and 60% are good. Tree B gives her 15 oranges and 1/3 are good. If she gets 55 good oranges per month, how many total trees does she have? Each tree A gives her six good oranges a month 10 x .6 = <<10*.6=6>>6 Each tree B gives her five good oranges a month because 15 x (1/3) = <<15*(1/3)=5>>5 On average, a tree gives her 5.5 oranges a month because .5(6) + .5(5) = 5.5 She has ten total trees because 55 / 5.5 = <<55/5.5=10>>10 #### 10 Michael bought 6 crates of egg on Tuesday. He gave out 2 crates to Susan, who he admires and bought another 5 crates on Thursday. If one crate holds 30 eggs, how many eggs does he have now? He had 6 crates and then gave out 2 so he now has 6-2 = <<6-2=4>>4 crates left He bought an additional 5 crates for a total of 4+5 = <<4+5=9>>9 crates Each crate has 30 eggs so he has 30*9 = <<30*9=270>>270 eggs #### 270 In a class, there were 13 female students. There were three times as many male students in this class. How many students were in the class? There were 13 * 3 = <<13*3=39>>39 male students in the class. In total the class had 39 students + 13 students = <<39+13=52>>52 students. #### 52 Harly's animal shelter has 80 dogs. She adopts out 40% of them but then has to take back 5 because of personality conflicts with other dogs in their adopted homes. How many dogs does she have now? First find how many dogs are adopted out: 80 dogs * 40% = <<80*40*.01=32>>32 dogs Then subtract the number of dogs adopted out from the total number of dogs and add the number who were returned to find the final number of dogs: 80 dogs - 32 dogs + 5 dogs = <<80-32+5=53>>53 dogs #### 53 Jo-Bob hopped into the hot air balloon, released the anchor rope, and pulled on the lift chain, which ignited the flame and provided the warm air that caused the balloon to rise. When the lift chain was pulled, the balloon would rise at a rate of 50 feet per minute. But when the chain was not being pulled, the balloon would slowly descend at a rate of 10 feet per minute. During his balloon ride, he pulled the chain for 15 minutes, then released the rope for 10 minutes, then pulled the chain for another 15 minutes, and finally released the chain and allowed the balloon to slowly descend back to the earth. During his balloon ride, what was the highest elevation reached by the balloon? The first 15-minute chain pull caused the balloon to rise 50*15=<<50*15=750>>750 feet. Releasing the chain for 10 minutes caused the balloon to descend 10*10=<<10*10=100>>100 feet. The second 15-minute chain pull caused the balloon to rise another 50*15=<<50*15=750>>750 feet. Thus, at the end of the second chain pull, when the balloon was at its highest elevation, the balloon had risen to an elevation of 750-100+750=<<750-100+750=1400>>1400 feet above the earth's surface. #### 1400 Every day Janet spends 8 minutes looking for her keys and another 3 minutes complaining after she finds them. If Janet stops losing her keys, how many minutes will she save every week? First find the total time Janet spends looking for her key and complaining each day: 8 minutes/day + 3 minutes/day = <<8+3=11>>11 minutes/day Then multiply that number by the number of days in a week to find the weekly time spent: 11 minutes/day * 7 days/week = <<11*7=77>>77 minutes #### 77