Tom needs to lower a rope down 6 stories. One story is 10 feet. The only rope being sold is 20 feet long but you lose 25% when lashing them together. How many pieces of rope will he need to buy?

He needs 10*6=

<<10*6=60>>60 feet He loses 20*.25=<<20*.25=5>>5 feet each time So he gets 20-5=<<20-5=15>>15 feet from each piece That means he needs 60/15=<<60/15=4>>4 pieces of rope #### 4 Samuel swept the porch and cleared nine-tenths of the dust particles from it. As he walked across the porch afterward, his shoes left 223 dust particles behind. How many dust particles were on the porch before Samuel swept if there were 331 after he walked across it? Before Samuel walked across the porch, there were 331 - 223 = <<331-223=108>>108 dust particles. Those 108 were 1/10 of the original amount, so there were 108 * 10 = <<108*10=1080>>1080 dust particles on the porch before Samuel swept. #### 1080 In a 90-minute soccer game, Mark played 20 minutes, then rested after. He then played for another 35 minutes. How long was he on the sideline? Mark played for a total of 20 + 35 = <<20+35=55>>55 minutes. So, he was on the sideline for 90 - 55 = <<90-55=35>>35 minutes. #### 35 Kim's TV uses 125 watts of electricity per hour. She runs it for 4 hours a day. If electricity cost 14 cents per kw/h how many cents does her TV cost to run for a week? She uses 4 hours/day * 125 watts/hour=<<4*125=500>>500 watt hours/day That means she uses 500 watt hours/day * 7 days/week = <<500*7=3500>>3500 watt hours/week This is 3500 watt hours / 1000 watts/kw = <<3500/1000=3.5>>3.5 kw hours So her TV cost 3.5 kw hours/week * $0.14/kw hour = $<<3.5*0.14=0.49>>0.49/week #### 49 Archie is playing with his marbles outside. He loses 60% of them into the street. Of the remaining ones, he loses half down a sewer. If he has 20 left, how many did he start with? He had 40 before losing them into the sewer because 20 x 2 =<<40=40>>40 He started with 100 because 40/.4=<<100=100>>100 #### 100 Adam earns $40 daily in his job. 10% of his money is deducted as taxes. How much money will Adam have earned after taxes after 30 days of work? The amount of money deducted from Adam's daily pay is $40 / 10 = $<<40/10=4>>4. So after deducting 10%, Adam’s daily pay is $40 – $4 = $<<40-4=36>>36. This means that in 30 days he earns $36 * 30 = $<<36*30=1080>>1080. #### 1,080 Lucille is painting her room. Two of her walls are 3 meters wide and 2 meters tall. The third wall is 5 meters wide and 2 meters tall. The final wall is 4 meters wide and 2 meters tall. If each can of paint covers 2 square meters, how many cans of paint does Lucille need? For the first set of walls, each wall covers 3 meters wide * 2 meters tall = <<3*2=6>>6 square meters. There are two of these walls, so this becomes a total of 6 meters * 2 walls = <<6*2=12>>12 square meters. The third wall covers 5 meters wide * 2 meters tall = <<5*2=10>>10 square meters. The final wall covers 4 meters wide * 2 meters tall = <<4*2=8>>8 square meters. So in total, the paint needs to cover 12 + 10 + 8 = <<12+10+8=30>>30 metres. Since each can covers 2 meters, Lucille needs 30 meters / 2 = <<30/2=15>>15 cans of paint. #### 15 Jeremy listened to five fewer songs yesterday than today. Yesterday, he listened to nine songs. How many songs did Jeremy listen to in two days? Jeremy listened to 9 + 5 = <<9+5=14>>14 songs today. Thus, he listened to 9 + 14 = <<9+14=23>>23 songs in two days. #### 23 Brian can only hold his breath underwater for 10 seconds. He wants to get better, so he starts practicing. After a week, he's doubled the amount of time he can do it. After another week, he's doubled it again from the previous week. The final week, he's increased it by 50% from the previous week. How long can Brian hold his breath for now? At the end of his first week, Brian now has doubled his initial time of 10 seconds to 10*2=<<10*2=20>>20 seconds At the end of his second week, Brian doubled the previous week's time of 20 seconds to 20*2=<<20*2=40>>40 seconds At the end of his third week of practice, Brian adds another 50% of 40 seconds to his time so 40*.5= <<40*.5=20>>20 seconds added Having added 20 seconds to his time from his second week, Brian can now hold his breath for 40+20= <<20+40=60>>60 seconds #### 60 A farmer has twice as many pigs as cows, and 4 more cows than goats. If the farmer has 56 animals total, how many goats does he have? Let x be the number of goats Cows:4+x Pigs:2(4+x)=8+2x Total:x+4+x+8+2x=56 4x+12=56 4x=44 x=<<11=11>>11 goats #### 11