It costs $.10 to print one page. Jenny wants to print 7 copies of her 25-page essay. She also wants to buy 7 pens that each cost $1.50. If she pays the store with 2 twenty dollar bills, how much money should she get in change?

Jenny needs to print 7*25=

<<7*25=175>>175 pages. This will cost 175*$.10 =$<<175*.10=17.5>>17.5. The pens will cost 7*$1.50=$<<7*1.5=10.50>>10.50. In total, she will spend $17.5+$10.5=$<<17.5+10.5=28>>28. Since she pays with 2 twenty dollar bills she pays with 2*20=<<2*20=40>>40 dollars. Thus, she will get $40-$28=$<<40-28=12>>12 in change. #### 12 240 sixth-grade students were asked about the number of novels they read per month. 1/6 of students read three or more novels, 35% of students read two novels, 5/12 of students read one novel, and the rest of the students do not read anything. Calculate the number of students who do not read novels. 1/6 * 240 students = <<1/6*240=40>>40 students. So 40 students read three or more novels. 35/100 * 240 students = <<35/100*240=84>>84 students. So 84 students read two novels. 5/12 * 240 students = <<5/12*240=100>>100 students. So 100 students read a novel. 240 students – (40 students + 84 students + 100 students) = 240 students – 224 students = <<240-(40+84+100)=16>>16 students. So 16 students don't read novels. #### 16 Carrie is wrapping three birthday presents. One present needs two square feet of wrapping paper to cover. The second present needs three-quarters of that amount. The third present needs the same amount as both other presents put together. How many square feet of wrapping paper does Carrie need for all three presents? The second present needs 3 / 4 * 2 = 1 1/2 square feet of wrapping paper. The third present needs 2 + 1 1/2 = 3 1/2 square feet of wrapping paper. Therefore, Carrie needs 2 + 1 1/2 + 3 1/2 = 7 square feet of wrapping paper for all three presents. #### 7 Tommy is making 12 loaves of bread. He needs 4 pounds of flour per loaf. A 10-pound bag of flour costs $10 and a 12-pound bag costs $13. When he is done making his bread, he has no use for flour and so he will throw away whatever is left. How much does he spend on flour if he buys the cheapest flour to get enough? He needs 48 pounds of flour because 12 x 4 = <<12*4=48>>48 He needs 4.8 bags of 10 pound bags because 48 / 10 = <<48/10=4.8>>4.8 He therefore needs to buy 5 bags of flour because 4 < 4.8 < 5 He spends $50 if he buys this flour because 5 x 10 = <<5*10=50>>50 He needs 4 bags of the 12-pound flour because 48 / 12 = <<48/12=4>>4 He would spend $52 on the 12-pound bags because 4 x 13 = 52 He spends $50 if he buys the cheapest flour because 50 < 52 #### 50 Cary is an engineer in charge of designing an irrigation system for three farmers. Farmer Bob grows 3 acres of corn, 9 acres of cotton, and 12 acres of beans. Farmer Brenda grows 6 acres of corn, 7 acres of cotton, and 14 acres of beans. Farmer Bernie grows 2 acres of corn and 12 acres of cotton. If corn takes 20 gallons of water an acre, cotton takes 80 gallons of water an acre, and beans take twice as much water as corn, what percentage of the total water used will go to Farmer Bob's farm? First figure out how much water beans take by multiplying the water use for corn by 2: 20 gallons/acre * 2 = <<20*2=40>>40 gallons/acre Next, calculate Bob's water use by multiplying each plant's water use per acre by the number of acres he planted, then adding up the total water use for all three crops: 3 * 20 + 9 * 80 + 12 * 40 = <<3*20+9*80+12*40=1260>>1260 Now do the same thing for Brenda: 6 * 20 + 7 * 80 + 14 * 40 = <<6*20+7*80+14*40=1240>>1240 And do the same thing for Bernie: 2 * 20 + 12 * 80 = 1000 Now add up each farmer's water use to find the total water use: 1260 + 1240 + 1000 = <<1260+1240+1000=3500>>3500 Now divide Bob's water use by the total water use and multiply by 100 to find what percentage of the water he used: 1260 / 3500 * 100 = <<1260/3500*100=36>>36% #### 36 Tommy wants to earn enough money to buy 8 new books. Each book costs $5. If Tommy already has $13, how much does he need to save up? The books will cost $40 because 8 x 5 = <<8*5=40>>40 He needs to save up $27 because 40 - 13 = <<40-13=27>>27 #### 27 Parker is 4 inches shorter than Daisy. Daisy is 8 inches taller than Reese. If Reese is 60 inches tall, what is the average height for the three of them? Since Daisy is 6 inches taller than Reese, she must be 60 inches + 8 inches = 68 inches tall. Parker is 4 inches shorter than Daisy, making her 68 inches – 4 inches = <<68-4=64>>64 inches. The average height of the three of them is (60 inches + 68 inches + 64 inches) / 3 = <<(60+68+64)/3=64>>64 inches. #### 64 There are 110 calories in a serving of cheese. Rick buys the large blocks that have 16 servings per block. If Rick has already eaten 5 servings of cheese, how many calories are remaining in the block? The block has 16 servings and he has eaten 5 servings leaving 16-5 = <<16-5=11>>11 servings of cheese There are 11 servings of cheese left and each serving is 110 calories for a total of 11*110 = <<11*110=1210>>1,210 calories #### 1210 Jason is mixing a batch of black paint. He needs to add 2 grams of charcoal for every 30 ml of water. If he adds 900 ml of water, how much charcoal does he add? First find how many ml of water Jason needs for 1 gram of charcoal: 30 ml / 2 grams = <<30/2=15>>15 ml/g Then divide the amount of water Jason uses by the amount of water per gram of charcoal to find how much charcoal he uses: 900 ml / 15 ml/g = <<900/15=60>>60 g #### 60 Carl types at a speed of 50 words per minute. If he types continuously for 4 hours per day, how many words can he type in 7 days? The number of words that Carl can type per hour is 50 * 60 = <<50*60=3000>>3000 words. The number of words that Carl can type in 4 hours is 3000 * 4 = <<3000*4=12000>>12000 words. The number of words that Carl can type in 7 days is 12000 * 7 = <<12000*7=84000>>84000 words. #### 84000