Mary has a mystery book library. She started with 72 mystery books at the beginning of the year. She joined a book club that sent her 1 book each month of the year. She went to a bookstore halfway through the year and bought 5 more books, then bought 2 books at yard sales later. Her daughter gave her another book for her birthday, and her mother gave her a series of 4 books when Mary visited her. She donated 12 books she didn't want to read again to a charity shop and sold 3 to a used book store. How many books did she have at the end of the year?

How many books did Mary get from the book club? ** Mary got 1 * 12 =

<<1*12=12>>12 books from the book club. How many books did Mary buy? ** She bought 5 + 2 = <<5+2=7>>7 books. How many books did Mary get from her mother? ** She was given 1 + 4 = <<1+4=5>>5 books. How many books did Mary get rid of? ** She got rid of 12 + 3 = <<12+3=15>>15 books. How many books did Mary have at the end of the year? ** Thus, at the end of the year she had 72 + 12 + 7 + 5 - 15 = <<72+12+7+5-15=81>>81 books. #### 81 There are 20 sandcastles on Mark's beach, each with 10 towers. On Jeff's beach, there are three times as many castles as on Mark's beach, each with 5 towers. What is the combined total number of sandcastles and towers on Mark's and Jeff's beaches? How many towers are there at Mark's beach? ** The total number of towers at Mark's beach is 20*10 = <<20*10=200>>200 towers. How many sandcastles and towers are there on Mark's beach? ** There are 200+20 = <<200+20=220>>220 sandcastles and towers on Mark's beach. How many sandcastles are there on Jeff's beach? ** Jeff's beach has 3*20 = <<3*20=60>>60 sandcastles, three times as many as the number of sandcastles in Mark's beach. How many towers are there in each of the sandcastles on Jeff's beach? ** The number of towers in each of the sandcastles on Jeff's beach is 1/2*10 = <<1/2*10=5>>5 How many towers are there on Jeff's beach? ** Since each sandcastle has 5 towers on Jeff's beach, there are 5*60 = <<5*60=300>>300 towers. How many towers and sandcastles are there on Jeff's beach? ** In total, on Jeff's beach, there are 300+60 = <<300+60=360>>360 towers and sandcastles. What is the combined total number of sandcastles and towers on Mark's and Jeff's beaches? ** Altogether, 360+220 = <<360+220=580>>580 sandcastles and towers can be found on their beaches. #### 580 Mr. Roper cuts his lawn 15 days a month beginning in April and ending in September. From October to the end of March he cuts his lawn three times a month. What is the average number of times that Mr. Roper cuts his yard per month? How many times does Mr. Roper cut his yard in 6 months? ** For 6 months of the year he cuts his yard 15 days per month so he cuts his yard 6*15 = <<6*15=90>>90 times How many times does Mr. Roper cut his yard in 6 months? ** For the remaining 6 months of the year, he cuts his yard three times a month so he cuts his yard 6*3 = <<6*3=18>>18 times How many times does Mr. Roper cut his yard in a year? ** He cuts his yard 90 times for part of the year and 18 times for the rest of the year for a total of 90+18 = <<90+18=108>>108 times What is the average number of times that MrS. Roper cuts his yard per month? ** There are 12 months in a year and he cuts his yard 108 times so he averages 108/12 = <<108/12=9>>9 times per month #### 9 Together 3 friends watched 411 short videos. Kelsey watched 43 more than Ekon. Ekon watched 17 less than Uma. How many videos did Kelsey watch? Define a variable ** Let U = the number of videos Uma watched How many videos did Ekon watch? ** Ekon = U - 17 How many videos did Kelsey watch? ** Kelsey = (U - 17) + 43 = U + <<(-17)+43=26>>26 Write an equation ** U + U - 17 + U + 26 = 411 Simplify ** 3U + 9 = 411 Simplify ** 3U = 402 Divide by 3 ** U = <<134=134>>134 How many videos did Kelsey watch? ** Kelsey = 134 + 26 = <<134+26=160>>160 videos How many videos did Kelsey watch? ** Kelsey watched 160 videos. #### 160 Tall Tuna has twice as many fish as Jerk Tuna. If Jerk Tuna has one hundred forty-four fish, how many fish do they have together? How many fish does Jerk Tuna have? ** If Jerk Tuna has one hundred forty-four fish, then Tall Tuna has 2*144 = 288 fish How many fish do they have together? ** Together, they have 288+144= <<288+144=432>>432 fish #### 432 Tedra is harvesting his tomatoes. He harvests 400 kg on Wednesday, and half as much on Thursday. He harvests a total of 2000 kg on Wednesday, Thursday, and Friday. How many tomatoes of the number he harvested on Friday are remaining if he gives away 700kg of them to his friends? How many tomatoes does Tedra harvest on Thursday? ** Tedra harvests 1/2 * 400 kg = <<1/2*400=200>>200 kg of tomatoes on Thursday. How many tomatoes does Tedra harvest on Friday? ** Tedra harvests 2000 kg - 400 kg - 200 kg = <<2000-400-200=1400>>1400 kg of tomatoes on Friday. How many tomatoes of the number he harvested on Friday are remaining if he gives away 700kg of them to his friends? ** After giving away tomatoes to his friends, he is left with 1400 kg - 700 kg = <<1400-700=700>>700 kg of tomatoes. #### 700 The tornado picked up the Smith's car and transported it 200 feet in the air before dropping it into the neighbors' pool. Also in the pool was a lawn chair that had been blown twice as far as the car had been transported. And the pool also contained a birdhouse that had flown through the air three times farther than the lawn chair had been blown. How far, in feet, far had the birdhouse flown? How far was the lawn chair blown? ** The lawn chair was blown twice as far as the car, or 2*200=<<2*200=400>>400 feet. How far had the birdhouse flown? ** The birdhouse had flown 3 times farther than the lawn chair had been blown, or 3*400=<<3*400=1200>>1200 feet. #### 1,200 In the school election, Eliot got twice as many votes as Shaun, and Shaun got 5 times as many votes as Randy. If Randy got 16 votes, how many did Eliot get? How many votes did Shaun get? ** Shaun got 5*16=<<5*16=80>>80 votes How many votes did Eliot get? ** Eliot got 80*2=<<80*2=160>>160 votes #### 160 Linda makes $10.00 an hour babysitting. There is a $25.00 application fee for each college application she submits. If she is applying to 6 colleges, how many hours will she need to babysit to cover the application fees? How much is the application fee? ** The application fee is $25.00 per college and she is applying to 6 colleges so that's 25*6 = $<<25*6=150.00>>150.00 How many hours does Linda need to babysit to cover the application fees? ** She makes $10.00 an hour babysitting. Her application fees total $150.00 so she needs to work 150/10 = <<150/10=15>>15 hours to cover the cost #### 15 A yearly book sale is held in school where students can sell their old books at a cheaper price. Two-fifths of Lovely's books can be sold for $2.50 each and the rest for $2 each. How much will Lovely earn if all 10 books were sold? How many books will Lovely sell for $2.50 each? ** Lovely will sell 10 x 2/5 = <<10*2/5=4>>4 books for $2.50 each. How many books will Lovely sell for $2 each? ** She will sell 10 - 4 = <<10-4=6>>6 books for $2 each. How much will Lovely earn from the 4 books at $2.50 each? ** Her earnings for the 4 books at $2.50 will be $2.50 x 4 = $<<2.5*4=10>>10. How much will Lovely earn from the 6 books for $2 each? ** Her earnings for the 6 books for $2 each will be $2 x 6 = $<<2*6=12>>12. How much will Lovely earn if all 10 books are sold? ** Thus, Lovely's total earning if all 10 books are sold is $10 + $12 = $22. #### 22