Brittany got a 78 on her first test. After her second test, her average rose to an 81. What grade did she get on her second test?

First multiply her average grade by the number of tests she took to find the total number of points she scored: 81 points * 2 =

<<81*2=162>>162 points Then subtract the number of points she scored on her first exam to find how many points she scored on her second exam: 162 points - 78 points = <<162-78=84>>84 points #### 84 Vins rides his bike 6 miles to school. He rides home a different route that is 7 miles long. This week, Vins rode to school and back 5 times. How many miles did Vins ride his bike this week? He rides his bike 6 + 7 = <<6+7=13>>13 miles to school and back every day. Therefore, Vins rode his bike 13 x 5 = <<13*5=65>>65 miles to school and back this week. #### 65 Eliza can iron a blouse in 15 minutes and a dress in 20 minutes. If she spends 2 hours ironing blouses and 3 hours ironing dresses, how many pieces of clothes did she iron? Since 60 minutes equal 1 hour, in 2 hours, Eliza ironed blouses for 2 x 60 = <<2*60=120>>120 minutes. Eliza can iron 120 / 15 = <<120/15=8>>8 blouses. Since 60 minutes equal 1 hour, in 3 hours, Eliza ironed dresses for 3 x 60 = <<3*60=180>>180 minutes. Eliza can iron 180 / 20 = <<180/20=9>>9 dresses. In total, Eliza ironed 8 + 9 = <<8+9=17>>17 pieces of clothes. #### 17 Jennifer bought twice as many candies as Emily and three times as many as Bob bought. If Emily bought 6 candies, how many candies did Bob buy? Jennifer bought twice as many as Emily (who bought 6 candies) which is 6*2 = <<6*2=12>>12 candies 12 candies (that Jennifer bought) is three times as much as what Bob bought which means 3*what Bob bought = 12 Dividing both sides of the equation by 3 gives: Number of candies Bob bought = 12/3 = <<12/3=4>>4 candies #### 4 Maria is baking cookies for Sally. Sally says that she wants 1/4 of her cookies to have nuts in them, 40% to have chocolate chips in them, and the remainder to have nuts and chocolate chips in them. When she adds nuts to the cookies, she uses 2 nuts per cookie. If she makes 60 cookies, how many nuts does she need? 35% of the cookies have nuts and chocolate chips because 100 - 25 - 40 = <<100-25-40=35>>35 60% of the cookies have nuts in them because 25 + 35 = <<25+35=60>>60 She makes 36 cookies with nuts in them because 60 x .6 =<<36=36>>36 She needs 72 nuts because 36 x 2 = <<36*2=72>>72 #### 72 An apartment building has 12 floors and half of them are full. The remaining floors are all at half-capacity. If each floor has 10 apartments and each apartment has four people, how many people are in the building? Half the floors are full, so there are 12 floors * 0.5 = <<12*0.5=6>>6 floors that are full. So the full floors contain 6 floors * 10 apartments = <<6*10=60>>60 apartments. The remaining floors are at half-capacity, so there are 12 floors – 6 full floors = <<12-6=6>>6 half-full floors. Each of these floors therefore contains 10 apartments * 0.5 = <<10*0.5=5>>5 apartments. So on the half-full floors, there are a total of 6 floors * 5 apartments = <<6*5=30>>30 apartments. In total, there are 30 + 60 = <<30+60=90>>90 filled apartments in the building. This means there are 90 apartments * 4 people per apartment = <<90*4=360>>360 people in the building. #### 360 Billy and Margaret are competing with each other to see who can swim 10 laps the fastest. Billy swims his first 5 laps in 2 minutes, swims the next 3 laps in 4 minutes, swims the next lap in 1 minute, then swims his final lap. Margaret finishes swimming all of her laps in 10 minutes. Billy wins the competition by finishing his laps 30 seconds before Margaret does. In seconds, how long did it take Billy to swim his final lap? Margaret finished all of her laps in 10 minutes * 60 seconds = <<10*60=600>>600 seconds. Billy’s first 5 laps took 2 minutes * 60 seconds = <<2*60=120>>120 seconds. His next 3 laps took 4 minutes * 60 seconds = <<4*60=240>>240 seconds. His ninth lap took 1 minute * 60 seconds = <<1*60=60>>60 seconds. So his first 9 laps took 120 + 240 + 60 = <<120+240+60=420>>420 seconds. Billy finished swimming his laps before Margaret so all of his laps took a total of 600 – 30 = <<600-30=570>>570 seconds. This means that it took 570 seconds in total swimming time – 420 seconds in time spent swimming the first 9 laps = 150 seconds for Billy to swim his final lap. #### 150 The town is having a race to see who can run around the town square 7 times the fastest. The town square is 3/4 of a mile long. The winner finishes the race in 42 minutes. Last year's winner finished in 47.25 minutes. How many minutes on average faster did this year's winner run one mile of the race compared to last year? The race is 5.25 miles long because 7 x .75 = <<7*.75=5.25>>5.25 They ran a mile in 8 minutes because 42 / 5.25 = <<42/5.25=8>>8 Last year's winner ran a mile in 9 minutes because 47.25 / 5.25 = <<47.25/5.25=9>>9 They ran 1 minute faster per mile compared to last year's winner. #### 1 Lisa has 18 more dresses than Ana. If the number of their dresses combined is 48, how many dresses does Ana have? If Lisa's surplus of 18 dresses is taken away from the total, they will have 48-18 = <<48-18=30>>30 dresses in total They would each have the same number of dresses from these 30 i.e. 30/2 = <<30/2=15>>15 dresses which is the number of dresses that Ana actually has. #### 15 Theo, Mason, and Roxy are siblings. Theo drinks 8 cups of water every day. Mason drinks 7 cups of water. Roxy drinks 9 cups of water every day. In one week, how many cups of water do the siblings drink together? Everyday, the three siblings drink 8 + 7 + 9 = <<8+7+9=24>>24 cups of water. In one week, they drink a total of 24 x 7 = <<24*7=168>>168 cups of water. #### 168