Osborn is testing a new way to get dressed in the morning on school days so he goes faster and can get up later. He tracks his time for the week and on Monday is takes him 2 minutes. On Tuesday it takes him 4 minutes. On Wednesday it takes him 3 minutes. On Thursday it takes him 4 minutes. Before Friday arrives he looks at his old way of getting dressed and sees that it was taking him 3 minutes on average to get dressed. How fast does he have to get dressed on Friday so his weekly average ties his old method?

How many minutes does it take on the school week? ** If it takes on average 3 minutes to get dressed, then it takes 15 minutes total on the school week because 5 x 3 =

<<15=15>>15 How many minutes has it taken him so far this week? ** Thus far this week it has taken him 13 minutes to get dressed because 2 + 4 + 3 + 4 = <<13=13>>13 How many minutes does he need on Friday? ** To tie his previous method, he needs to take 2 minutes on Friday because 15 - 13 = <<15-13=2>>2 #### 2 Rob and Mark plan to meet at the national park. It takes 1 hour for Rob to get to the national park and it takes three times as much time for Mark to get to the national park. If Rob leaves his home at 11 a.m., at what time should Mark leave his home so that they both arrive at the same time? How long does it take Mark to get to the national park? ** It takes 1 hour * 3 = <<1*3=3>>3 hours for Mark to get to the national park. How much extra time does Mark need to get to the national park? ** The extra time it takes Mark to get to the national park is 3 hours - 1 hour = <<3-1=2>>2 hours What time should Mark leave his home? ** Mark should leave his home at 11 a.m. - 2 hours = <<11-2=9>>9 a.m. #### 9 Jenny's property tax rate is 2%. Her house is currently worth $400,000. The city is about to build a new high-speed rail project nearby, which will increase her house's value by 25%. Jenny can only afford to spend $15,000/year on property tax. How many dollars worth of improvements can she make to her house before her property tax bill gets too high? How much will the rail project increase the house value? ** First find how much the rail project will increase the house value by multiplying the initial value by 25%: $400,000 * .25 = $<<400000*.25=100000>>100,000 How much will the house be worth after the rail project? ** Then add that amount to the initial value to find the new value: $100,000 + $400,000 = $<<100000+400000=500000>>500,000 How much can Jenny afford to pay in property tax? ** Then divide the maximum amount of property tax Jenny can afford to pay by the property tax rate to find the maximum value her house can have: $15,000 / .02 = $<<15000/.02=750000>>750,000 How much value can Jenny's improvements have? ** Now subtract the house's value after the rail project from the maximum value to find how much value the improvements can have: $750,000 - $500,000 = $<<750000-500000=250000>>250,000 #### 250000 If there are four times as many red crayons as blue crayons in a box, and there are 3 blue crayons. How many crayons total are in the box? How many red crayons are there? ** Red crayons: 4(3)=12 How many crayons total are there? ** Total crayons: 12+3=<<12+3=15>>15 crayons #### 15 Brenda raises mice, and her adult mice recently had three litters of 8 each. She gave a sixth of the baby mice to her friend Robbie to keep as pets. She sold three times the number of babies she gave Robbie to a pet store. Half of the remaining mice were sold to snake owners as feeder mice. How many baby mice did Brenda have left? How many baby mice did Brenda have? ** Brenda’s mice had 3 * 8 = <<3*8=24>>24 baby mice. How many baby mice did Brenda give Robbie? ** She gave Robbie 24 / 6 = <<24/6=4>>4 mice. How many baby mice did Brenda sell to the pet store? ** Thus, she sold 3 * 4 = <<3*4=12>>12 mice to the pet store. How many baby mice did Brenda have left? ** She had 24 - 12 - 4 = <<24-12-4=8>>8 mice remaining. How many baby mice did Brenda sell as feeder mice? ** She sold 8 / 2 = <<8/2=4>>4 as feeder mice. How many baby mice did Brenda have left? ** Thus, Brenda had 8 - 4 = <<8-4=4>>4 mice left. #### 4 A magazine costs $3 each. Jewel bought 10 magazines to be sold at $3.50 each. How much will be Jewel gain from selling these? How much will be Jewel gain from selling these? ** Jewel's gain for each magazine is $3.50 - $3 = $<<3.5-3=0.50>>0.50. How much will be Jewel gain from selling these? ** Thus, her total gain will be $0.50 x 10 = $<<0.50*10=5>>5. #### 5 Leila went to the supermarket to get some groceries. Then she headed to her mechanic to get her automobile fixed. If fixing her automobile cost $350 which was $50 more than thrice the amount she spent at the supermarket, how much has she spent altogether? How much did fixing her automobile cost? ** Reversing the steps to obtain the amount she spent at the supermarket, $50 less than $350 is $350-$50 = $<<350-50=300>>300 How much did Leila spend at the supermarket? ** If $300 was thrice the amount she spent at the supermarket, then the amount spent at the supermarket was $300/3 = $<<300/3=100>>100 How much has Leila spent altogether? ** In addition to what she spent fixing her auto, she spent $100+$350 = $<<100+350=450>>450 altogether #### 450 On a shopping trip in a crowded store, Josie had to wait 3 minutes for a cart, 13 minutes for an employee to unlock a cabinet to get her a product, 14 minutes for a stocker to restock a shelf with what she wanted, and 18 minutes in line to check out. Her shopping trip took an hour and a half. How many minutes did Josie spend shopping instead of waiting? How many minutes did Josie spend shopping? ** There are 60 minutes in an hour, so the trip took 1 1/2 * 60 = 90 minutes. How many minutes did Josie spend waiting? ** Josie spent 3 + 13 + 14 + 18 = <<3+13+14+18=48>>48 minutes waiting. How many minutes did Josie spend shopping? ** Thus, she spent 90 - 48 = <<90-48=42>>42 minutes shopping. #### 42 In 10 years, Terry will be 4 times the age that Nora is currently. If Nora is currently 10 years old, how old is Terry now? How old will Terry be in 10 years? ** Terry will be 4*10=<<4*10=40>>40 years old in 10 years How old is Terry now? ** How old is Terry now? ** Currently, Terry is 40-10 = <<40-10=30>>30 years old. #### 30 A frog lays 800 eggs a year. 10 percent dry up, and 70 percent are eaten. 1/4 of the remaining eggs end up hatching, how many frogs hatch out of the 800? How many eggs dry up? ** Dried up:800(.10)=80 eggs How many eggs are eaten? ** 800(.70)=560 eggs How many eggs are left? ** Total left:800-80-560=<<800-80-560=160>>160 eggs How many eggs end up hatching? ** 160/4=<<160/4=40>>40 eggs survive to hatch #### 40