Doris earns $20 per hour by babysitting. She needs to earn at least $1200 for her monthly expenses. She can babysit for 3 hours every weekday and 5 hours on a Saturday. How many weeks does it take for Doris to earn enough to cover her monthly expenses?

Doris babysits for a total of 5 weekdays x 3 hours/weekday =

<<5*3=15>>15 hours She babysits for a total of 15 + 5 = <<15+5=20>>20 hours in a week. She earns 24 x $20 = $<<24*20=480>>480 in a week. So, it will take $1440/$480 = <<1440/480=3>>3 weeks to earn Doris needed amount. #### 3 In a certain forest, there are 4 species of trees: oak, pine, spruce, and birch. There is a total of 4000 trees in the forest. Spruces make up 10% of all the trees, and pines 13%. There are as many oaks as spruces and pines put together. How many birches are there in the forest? There are 10/100 * 4000 = <<10/100*4000=400>>400 spruces in the forest There are 13/100 * 4000 = <<13/100*4000=520>>520 pines in the forest. There are as many oaks as pines and spruces together, so there are 400 + 520 = <<400+520=920>>920 oaks. Therefore there are 4000 - 920 - 520 - 400 = <<4000-920-520-400=2160>>2160 birches. #### 2160 Ellie takes her little brother down to the pond to teach him how to skip stones. After he takes his first throw, she gives him pointers to improve his technique. His second throw skips two more times across the water than his first. His third throw skips twice as many times as his second. His fourth throw skips 3 fewer times than his third throw. His fifth throw skips one more time than the fourth throw. If his fifth throw skipped 8 times across the water, how many skips did he make in total between all of his throws? His fourth throw made 8 - 1 = <<8-1=7>>7 skips. His third throw made 7 + 3 = <<7+3=10>>10 skips. His second throw made 10 / 2 = <<10/2=5>>5 skips. His first throw made 5 - 2 = <<5-2=3>>3 skips. The total number of skips is 8 + 7 + 10 + 5 + 3 = <<8+7+10+5+3=33>>33 skips. #### 33 John buys dinner plates and silverware. The silverware cost $20. The dinner plates cost 50% as much as the silverware. How much did he pay for everything? The dinner plates cost 20*.5=$<<20*.5=10>>10 So he paid 10+20=$<<10+20=30>>30 #### 30 Lynne bought 7 books about cats and 2 books about the solar system. She also bought 3 magazines. Each book cost 7$ and each magazine cost $4. How much did Lynne spend in all? Lynne bought a total of 7 + 2 = <<7+2=9>>9 books The books cost Lynne 9 x 7 = $<<9*7=63>>63 For 3 magazines, Lynne spent 3 x 4 = $<<3*4=12>>12 In total, Lynne spent 63 + 12 = <<63+12=75>>75$ #### 75 Jared likes to draw monsters. He drew a monster family portrait. The mom had 1 eye and the dad had 3. They had 3 kids, each with 4 eyes. How many eyes did the whole family have? The mom and dad monsters had 1 + 3 = <<1+3=4>>4 eyes. The 3 kids had 4 eyes each, so 3 x 4 = <<3*4=12>>12 eyes. Altogether, the monster family had 4 parent eyes + 12 child eyes = <<4+12=16>>16 eyes. #### 16 Tom bought his games for $200. They tripled in value and he then sold 40% of them. How much did he sell the games for? The value of the games increased to 200*3=$<<200*3=600>>600 So he sold 600*.4=$<<600*.4=240>>240 worth of games #### 240 Cathy has $12 left in her wallet. Her dad sent her $25 for her weekly consumption while her mom sent her twice the amount her dad sent her. How much money does Cathy have now? Cathy has $12 + $25 = $<<12+25=37>>37 after his father sent him money. Her mom sent her $25 x 2 = $<<25*2=50>>50. Therefore, Cathy has $50 + $37 = $<<50+37=87>>87. #### 87 At the Bertolli Farm, they grow 2073 tomatoes, 4112 cobs of corn, and 985 onions. How many fewer onions are grown than tomatoes and corn together? 2073 + 4112 = <<2073+4112=6185>>6185 6185 - 985 = <<6185-985=5200>>5200 The Bertolli Farm grows 5200 fewer onions than tomatoes and corn. #### 5200 Tom was putting hardwood flooring into his living room that measured 16' long and 20' wide. The flooring comes 10 sq ft per box and he has already put down 250 sq ft of flooring. How many more boxes does Tom need to complete the job? The entire sq ft of the living room is LxW so the room is 16x20 = <<16*20=320>>320 sq ft Tom has already put down 250 sq ft so he needs to put down 320-250 = 70 sq ft of flooring The boxes contain 10 sq ft of flooring per box and he needs 70 more sq ft of flooring so he needs 70/10 = <<70/10=7>>7 more boxes #### 7