Cara has 60 marbles in a bag. 20 of them are yellow, half as many are green, and the remaining marbles are equally divided between red and blue. If Cara picks a marble at random, what are the odds it's blue (expressed as a percentage)?

First find the number of green marbles: 20 yellow marbles / 2 =

<<20/2=10>>10 green marbles Then find how many marbles are either red or blue: 60 marbles - 20 yellow marbles - 10 green marbles = <<60-20-10=30>>30 marbles Divide this number in half to find how many marbles are blue: 30 marbles / 2 = <<30/2=15>>15 blue marbles Finally, divide the number of blue marbles by the total number of marbles and multiply by 100 to find the percentage chance of getting a blue marble: 15 marbles / 60 marbles * 100 = <<15/60*100=25>>25% #### 25 In 6 years, Carla will be 30 years old. The sum of the current ages of Carla and Louis is 55. How old is Louis now? Carla is currently 30-6=<<30-6=24>>24 years old. Louis is 55-24=<<55-24=31>>31 years old at present. #### 31 Jane sews 2 dresses a day for 7 days. Then she sews 3 dresses a day for the next 2 days. In the end, she adds 2 ribbons to each dress. How many ribbons does Jane use in total? In 7 days, Jane sews 2 * 7 = <<2*7=14>>14 dresses In the next 2 days, Jane sews 3 * 2 = <<3*2=6>>6 dresses Jane sews a total of 14 + 6 = <<14+6=20>>20 dresses Jane uses a total of 20 * 2 = <<20*2=40>>40 ribbons #### 40 Cary walks 3 miles round-trip to the grocery store, where he buys and eats a candy bar with 200 calories. If Cary burns 150 calories per mile walked, what's Cary's net calorie deficit (expressed as a positive number)? First, find how many calories the walk burned by multiplying the calories burned per mile by the number of miles Cary walked: 3 miles * 150 calories/mile = <<3*150=450>>450 calories Then subtract the calories Corey ate to find the net calories Cary burned: 450 calories - 200 calories = <<450-200=250>>250 calories #### 250 Mrs. Watson is grading 120 final exams from her American History class. On Monday, she grades 60% of the exams. On Tuesday, she grades 75% of the remaining exams. On Wednesday, how many more exams does she need to grade? On Monday, Mrs. Watson grades 120 x 60% = <<120*60*.01=72>>72 final exams. At the end of Monday, she has 120 - 72 = <<120-72=48>>48 exams left to grade. On Tuesday, she grades 48 x 75% = <<48*75*.01=36>>36 final exams. On Wednesday, she has 48 - 36 = <<48-36=12>>12 exams left to grade. #### 12 In Canada, for every moose there are two beavers, and for every beaver there are 19 humans. If there are 38 million people in Canada, what is the moose population of Canada, in millions? If there are 19 humans for every one beaver, then there are 38 million/19=<<38/19=2>>2 million beavers in Canada. And if for every one moose there are two beavers, then the moose population of Canada is 2 million/2=<<2/2=1>>1 million. #### 1 Matias is a salesman in a bookstore. He sold 7 books on Tuesday and three times as many on Wednesday. If the sales from Wednesday were tripled on Thursday, how many books did Matias sell during these three days combined? Matias sold 7 * 3 = <<7*3=21>>21 books on Wednesday, as he sold three times more books than on Tuesday. The sales from Wednesday were tripled on Thursday, which means Matias sold then 21 * 3 = <<21*3=63>>63 books. That means in total Matias sold 7 + 21 + 63 = <<7+21+63=91>>91 books during these three days. #### 91 On March 1st the sun sets at 6 PM. Every day after the sun sets 1.2 minutes later. It is 6:10 PM and 40 days after March 1st. How many minutes until the sun sets? The sun will set 40*1.2=<<40*1.2=48>>48 minutes later than it does on March 1st. That means the sun will set at 6:00+48=6:48 PM So that means the time until sunset is 6:48-6:10=<<648-610=38>>38 minutes #### 38 Titan's father has an onion farm ready for harvest. He borrows Mr. Clay's pickup and transports the harvest to their store, carrying ten bags per trip, prepared for sale. If the onions are in 50 kgs bags, and the pickup makes 20 trips, what's the total weight of onions harvested by Titan's father? On one trip, the pickup carries 10 bags * 50 kg/bag = <<10*50=500>>500kg of onions After 20 trips, the total weight of onions transported to the store is 20 trips * 500 kg/trip = <<20*500=10000>>10000 kgs #### 10000 A Lamplighter monkey has long arms and can swing from branch to branch at a speed of 10 feet per second. But when the monkey is frightened, it will run along the branches at a speed of 15 feet per second. If a Lamplighter monkey runs for 5 seconds to evade a predator, then swings for another 10 seconds to add distance between itself and the predator, how far, in feet, will the monkey travel? At a speed of 15 feet per second, for 5 seconds, the monkey will travel 5 * 15 = <<5*15=75>>75 feet. At a speed of 10 feet per second for 10 seconds, the monkey will travel 10 * 10 = <<10*10=100>>100 feet. In total, the monkey will travel 75+100=<<75+100=175>>175 feet. #### 175