The sum of Mario and Maria's ages now is 7. Mario is 1 year older than Maria. How old is Mario?

How old is Mario? ** If x is Maria's age, then Mario's age is x + 1.

How old are Mario and Maria? ** The equation that represents the sum of their ages is x + x + 1 = 7.

How old are Mario and Maria? ** By combining like terms, the equation becomes 2x = 6.

How old is Maria? ** Hence, the value of x which represents the age of Maria is 6/2=

<<6/2=3>>3. How old is Mario? ** So Mariu is 3 + 1 = <<3+1=4>>4 years old. #### 4 Maria wants to paint a picture and needs some tools to do that. She wants to buy a set of brushes for $20 and some canvas for three times more than the brushes. The paint costs Maria $8 per liter, and she needs at least 5 liters. How much money will she earn on the painting if she will be able to sell it for $200? How much does the canvas cost? ** Maria wants to pay 3 * 20 = $<<3*20=60>>60 for the canvas. How much does the paint cost? ** Maria needs 5 liters of paint, so the cost of it would be 8 * 5 = $<<8*5=40>>40. How much money will Maria earn on the painting? ** So in total Maria will earn 200 - 40 - 60 - 20 = $<<200-40-60-20=80>>80 if she will be able to sell the painting at the mentioned price. #### 80 In preparation for his mountain climbing, Arvin wants to run a total of 20 kilometers in a week. On the first day, he ran 2 kilometers. On each subsequent day, he increased his running distance by 1 kilometer over the previous day. If he runs for 5 days a week, how many kilometers did he run on the 5th day? How many kilometers did Arvin run on the second day? ** On the second day, Arvin ran 2 + 1 = <<2+1=3>>3 kilometers. How many kilometers did Arvin run on the third day? ** On the third day, he ran 3 + 1 = <<3+1=4>>4 kilometers. How many kilometers did Arvin run on the fourth day? ** On the fourth day, he ran 4 + 1 = <<4+1=5>>5 kilometers. How many kilometers did Arvin run on the fifth day? ** So on the fifth day, he ran 5 + 1 = <<5+1=6>>6 kilometers. #### 6 Compared to the amount of water she drank, Carla drank three times as much soda minus 6 ounces. If she drank 54 ounces of liquid total, how much water did she drink? How many ounces of water did Carla drink? ** Let s be the amount of soda Carla drank and w be the amount of water she drank. We know that s + w = 54 and s = 3w - 6. Substituting the second equation into the first, we get 3w - 6 + w = 54. How many ounces of water did Carla drink? ** Combining like terms, we get 4w - 6 = 54 How many ounces of water did Carla drink? ** Adding 6 to both sides, we get 4w = 60 How many ounces of water did Carla drink? ** Dividing both sides by 4, we get w = 15 #### 15 Xavier needs 84 paper plates for a housewarming party. He already has 21 green plates and 28 red plates. How many more plates should Xavier buy? How many plates does Xavier have? ** The total number of green and red plates is 28 + 21 = <<28+21=49>>49. How many more plates should Xavier buy? ** Xavier should buy 84 − 49 = 35 more plates. #### 35 Every 10 seconds, there is a car collision, and every 20 seconds there is a big crash. How many accidents overall will happen in 4 minutes? How many seconds are in 4 minutes? ** 1 minute is 60 seconds, so 4 minutes is 4 * 60 = <<4*60=240>>240 seconds. How many big crashes will there be in 4 minutes? ** During this time there would be 240 / 20 = <<240/20=12>>12 big crashes. How many car collisions will there be in 4 minutes? ** And also 240 / 10 = <<240/10=24>>24 car collisions. How many accidents will there be in 4 minutes? ** So in total during 4 minutes there would be 12 + 24 = <<12+24=36>>36 accidents. #### 36 Zack has traveled to twice the number of countries Patrick traveled to. Patrick traveled to three times the number of countries Joseph traveled to. Joseph traveled to half the number of countries George traveled to. If George traveled to 6 countries, how many countries did Zack travel to? How many countries did Joseph travel to? ** Joseph traveled to 6 / 2 = <<6/2=3>>3 countries. How many countries did Patrick travel to? ** Patrick traveled to 3 * 3 = <<3*3=9>>9 countries. How many countries did Zack travel to? ** So, Zack traveled to 2 * 9 = <<2*9=18>>18 countries. #### 18 Christian and Sue wanted to get a $50.00 bottle of perfume for their mom for her birthday. Christian had $5.00 saved up and Sue had $7.00. Christian then mowed 4 of his neighbors' yards, charging $5.00 each, while Sue walked 6 dogs for her neighbors, charging $2.00 per dog. How much more money will Christian and Sue need to make in order to buy the bottle of perfume for their mom? How much money did Christian make mowing yards? ** Christian just mowed 4 yards at $5.00 each so he made 4*5 = $<<4*5=20.00>>20.00 How much money did Sue make walking dogs? ** Sue just walked 6 dogs at $2.00 each so she made 6*2 = $<<6*2=12.00>>12.00 How much money did Christian and Sue have together? ** Christian had $5.00 saved and just made $20.00 while Sue had $7.00 saved and just made $12.00 so together they had 5+20+7+12 = $<<5+20+7+12=44>>44 How much more money will Christian and Sue need to make in order to buy the bottle of perfume for their mom? ** The perfume cost $50.00 and they had $44.00 so they needed to make 50-44 = $<<50-44=6.00>>6.00 more dollars #### 6 Betty and Dora started making some cupcakes at the same time. Betty makes 10 cupcakes every hour and Dora makes 8 every hour. If Betty took a two-hour break, what is the difference between the number of cupcakes they made after 5 hours? How many cupcakes did Dora make? ** Dora made 8 cupcakes per hour for 5 hours for a total of 8*5 = <<8*5=40>>40 cupcakes How many hours did Betty spend making cupcakes? ** Betty took a 2-hour break so she spent 5-2 = <<5-2=3>>3 hours making cupcakes How many cupcakes did Betty make? ** Betty made 10 cupcakes per hour for 3 hours for a total of 10*3 = <<10*3=30>>30 cupcakes What is the difference between the number of cupcakes they made after 5 hours? ** The difference between the number of cupcakes they made is 40-30 = <<40-30=10>>10 cupcakes #### 10 A clerk can process 25 forms per hour. If 2400 forms must be processed in an 8-hour day, how many clerks must you hire for that day? How many forms can one clerk process in an 8-hour day? ** One clerk can process 25 x 8 = <<25*8=200>>200 forms in a day. How many clerks must be hired for that day? ** To process the forms for that day 2400/200 = <<2400/200=12>>12 clerks must be hired. #### 12