The Smiths and the Johnsons were competing in the final leg of the Amazing Race. In their race to the finish, the Smiths immediately took off on a 165 kilometer path traveling at an average speed of v kilometers per hour.The Johnsons' start was delayed by 21 hour. Eventually, they took a 180 kilometer path to the finish, traveling at an average speed that was 20 kilometers per hour faster than the Smiths' speed.The Johnsons arrived at the finish line first and won the race!Write an inequality in terms of v that models the situation.
Q. The Smiths and the Johnsons were competing in the final leg of the Amazing Race. In their race to the finish, the Smiths immediately took off on a 165 kilometer path traveling at an average speed of v kilometers per hour.The Johnsons' start was delayed by 21 hour. Eventually, they took a 180 kilometer path to the finish, traveling at an average speed that was 20 kilometers per hour faster than the Smiths' speed.The Johnsons arrived at the finish line first and won the race!Write an inequality in terms of v that models the situation.
Denoting the average speed: Let's denote the average speed of the Smiths as v kilometers per hour. The Smiths travel a distance of 165 kilometers.The time it takes for the Smiths to complete their path is given by the formula:Time = Distance / SpeedSo for the Smiths, the time is:TimeSmiths=v165
Calculating the Smiths' time: The Johnsons' average speed is 20 kilometers per hour faster than the Smiths', so their speed is v+20 kilometers per hour. They travel a distance of 180 kilometers.The time it takes for the Johnsons to complete their path is given by the same formula:Time = Distance / SpeedSo for the Johnsons, the time is:TimeJohnsons=v+20180
Determining the Johnsons' speed: The Johnsons started 21 hour later than the Smiths. To account for this delay, we add 21 hour to the Johnsons' travel time.Adjusted TimeJohnsons=TimeJohnsons+21Adjusted TimeJohnsons=v+20180+21
Calculating the Johnsons' time: The Johnsons arrived at the finish line first, which means their adjusted time must be less than the time it took the Smiths.So the inequality that models the situation is:Adjusted TimeJohnsons < TimeSmiths\frac{180}{v + 20} + \frac{1}{2} < \frac{165}{v}
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