Bella bought stamps at the post office. Some of the stamps had a snowflake design, some had a truck design, and some had a rose design. Bella bought 11 snowflake stamps. She bought 9 more truck stamps than snowflake stamps, and 13 fewer rose stamps than truck stamps. How many stamps did Bella buy in all?

The number of truck stamps is 11 + 9 =

<<11+9=20>>20. The number of rose stamps is 20 − 13 = <<20-13=7>>7. Bella bought 11 + 20 + 7 = <<11+20+7=38>>38 stamps in all. #### 38 Each bird eats 12 beetles per day, each snake eats 3 birds per day, and each jaguar eats 5 snakes per day. If there are 6 jaguars in a forest, how many beetles are eaten each day? First find the total number of snakes eaten: 5 snakes/jaguar * 6 jaguars = <<5*6=30>>30 snakes Then find the total number of birds eaten per day: 30 snakes * 3 birds/snake = <<30*3=90>>90 snakes Then multiply the number of snakes by the number of beetles per snake to find the total number of beetles eaten per day: 90 snakes * 12 beetles/snake = <<90*12=1080>>1080 beetles #### 1080 Samantha’s last name has three fewer letters than Bobbie’s last name. If Bobbie took two letters off her last name, she would have a last name twice the length of Jamie’s. Jamie’s full name is Jamie Grey. How many letters are in Samantha’s last name? There are 4 letters in Jamie’s last name, so Bobbie’s name is 4*2 +2 = <<4*2+2=10>>10 letters long. Samantha’s last name is 3 letters shorter than Bobbie’s, so there are 10 - 3 = <<10-3=7>>7 letters in Samantha’s last name. #### 7 Ann's favorite store was having a summer clearance. For $75 she bought 5 pairs of shorts for $7 each and 2 pairs of shoes for $10 each. She also bought 4 tops, all at the same price. How much did each top cost? She bought 5 shorts at $7 each so 5*7=$<<5*7=35>>35 She bought 2 pair of shoes at $10 each so 2*10=$<<2*10=20>>20 The shorts and shoes cost her 35+20 = $<<35+20=55>>55 We know she spent 75 total and the shorts and shoes cost $55 which left a difference of 75-55 = $<<75-55=20>>20 She bought 4 tops for a total of $20 so 20/4 = $5 #### 5 Mary does her grocery shopping on Saturday. She does her shopping only at a specific store where she is allowed a credit of $100, which must be paid in full before her next shopping trip. That week she spent the full credit limit and paid $15 of it on Tuesday and $23 of it on Thursday. How much credit will Mary need to pay before her next shopping trip? So far, Mary has paid back $15 +$23=$<<15+23=38>>38 of the credit. So she still needs to pay $100-$38=$<<100-38=62>>62 #### 62 Ralph is going to practice playing tennis with a tennis ball machine that shoots out tennis balls for Ralph to hit. He loads up the machine with 175 tennis balls to start with. Out of the first 100 balls, he manages to hit 2/5 of them. Of the next 75 tennis balls, he manages to hit 1/3 of them. Out of all the tennis balls, how many did Ralph not hit? Out of the first 100 balls, Ralph was able to hit 2/5 of them and not able to hit 3/5 of them, 3/5 x 100 = 60 tennis balls Ralph didn't hit. Out of the next 75 balls, Ralph was able to hit 1/3 of them and not able to hit 2/3 of them, 2/3 x 75 = 50 tennis balls that Ralph didn't hit. Combined, Ralph was not able to hit 60 + 50 = <<60+50=110>>110 tennis balls Ralph didn't hit. #### 110 Jack is stranded on a desert island. He wants some salt to season his fish. He collects 2 liters of seawater in an old bucket. If the water is 20% salt, how many ml of salt will Jack get when all the water evaporates? First find how many liters of the seawater are salt: 2 liters * 20% = <<2*20*.01=.4>>.4 liters Then multiply that amount by 1000 ml/liter to find the number of ml of salt Jack gets: .4 liters * 1000 ml/liter = <<.4*1000=400>>400 ml #### 400 Brennan was researching his school project and had to download files from the internet to his computer to use for reference. After downloading 800 files, he deleted 70% of them because they were not helpful. He downloaded 400 more files but again realized that 3/5 of them were irrelevant. How many valuable files was he left with after deleting the unrelated files he downloaded in the second round? The number of non-valuable files Brennan downloaded in the first round is 70/100*800 = <<70/100*800=560>>560 files. The number of valuable files Brennan downloaded in the first round is 800-560 = <<800-560=240>>240 When he downloaded 400 new files, there were 3/5*400= <<3/5*400=240>>240 non-useful files, which he deleted again. The total number of valuable files he downloaded in the second round is 400-240 = <<400-240=160>>160 To write his research, Brennan had 160+240 = <<160+240=400>>400 useful files to reference to write his research. #### 400 There are 5 houses on a street, and each of the first four houses has 3 gnomes in the garden. If there are a total of 20 gnomes on the street, how many gnomes does the fifth house have? In the first four houses, there are a total of 4 houses * 3 gnomes = <<4*3=12>>12 gnomes. Therefore, the fifth house had 20 total gnomes – 12 gnomes = <<20-12=8>>8 gnomes. #### 8 Mrs. Snyder used to spend 40% of her monthly income on rent and utilities. Her salary was recently increased by $600 so now her rent and utilities only amount to 25% of her monthly income. How much was her previous monthly income? Let her previous monthly income be p The cost of her rent and utilities was 40% of p which is (40/100)*p = 2p/5 Her income was increased by $600 so it is now p+$600 The cost of her rent and utilities now amount to 25% of (p+$600) which is (25/100)*(p+$600) = (p+$600)/4 Equating both expressions for cost of rent and utilities: 2p/5 = (p+$600)/4 Multiplying both sides of the equation by 20 gives 8p = 5p+$3000 Subtracting 5p from both sides gives: 3p = $3000 Dividing both sides by 3 gives p = $1000 #### 1000