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?

In the bottom half of the igloo, there are 10 rows / 2 =

<<10/2=5>>5 rows of bricks of snow. 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. 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. 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? Let X be my age now. In ten years, I'll be X+<<+10=10>>10 years old. In ten years, my brother will be (X+10)*1/2 years old. In ten years, (X+10) + (X+10)*1/2 = 45. So (X+10)*3/2 = 45. X+10 = 45 * 2/3 = 30. 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? After the birds ate 19 of the tomatoes Haruto has 127 - 19 = <<127-19=108>>108 tomatoes 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? 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. 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. Combined, the three holes leak at a rate of 3+1.5+0.5=<<3+1.5+0.5=5>>5 ounces per minute. Since one hour is 60 minutes, two hours is 2*60=<<2*60=120>>120 minutes. 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? Robin ate twice as many buttercream cupcakes as chocolate sauce cupcakes, or 2 * 4 = <<2*4=8>>8. 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? If 30 kids each make 8 cards, they will have made 240 cards because 30*8 = <<30*8=240>>240. 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. If Harvey ran 8 more miles, then he ran a total of 12 miles + 8 miles = <<12+8=20>>20 miles. The two friends ran a total of 20 miles + 12 miles = <<20+12=32>>32 miles #### 32 Jeff spends three times as many hours on the weekend catching up with his Facebook pals as he does working. Monday through Friday, however, he spends four times as many hours working as he does catching up. If he spends 3 hours every day catching up, how many hours does he spend working in an entire week? On the weekend, Jeff works 3 / 3 = <<3/3=1>>1 hour each day. On the weekdays, he spends 4 * 3 = <<4*3=12>>12 hours working each day. Thus, he spends 2 * 1 + 5 * 12 = <<2*1+5*12=62>>62 hours working each week. #### 62 John worked 8 hours a day every day from the 3rd to the 8th, including the 3rd and not including the 8th. How many hours did he work? He worked for 8-3=<<8-3=5>>5 days So he worked for 5*8=<<5*8=40>>40 hours #### 40 A library has 7 rectangular tables and the remaining tables will be square tables. A rectangular table seats 10 pupils while a square table seats 4 pupils. How many square tables are needed so that 90 pupils can read at the same time? The rectangular tables seat 7*10=<<7*10=70>>70 pupils. The square tables will seat 90-70=<<90-70=20>>20 pupils. The library needs 20/4=<<20/4=5>>5 square tables. #### 5