Rate of change (Level 3 word problems) Quiz

<p>A truck driver checked his refrigerated trailer's temperature before and after their deliveries yesterday.</p><ul><li> The temperature in the trailer at the beginning of the day was `4°`F. </li><li>The temperature in the trailer decreased `6°`F per hour for `3` hours while they drove.</li><li>During the next delivery, the temperature in the truck's refrigerated trailer increased by `2°`F per hour for `2` hours.</li></ul><p>Questions:<p><ul><li>What was the temperature after `3` hours?</li><li> What was the temperature after the following `2` hours?</li></ul><p><highlight data-color="#666" data-style="italic">Round to the nearest hundredth if needed. </highlight><p>

<p>In 1980, the closing balance of the account of Mrs. Sullivan was `$33500`. She added funds to it at a steady rate of `$450` per year for the next `25` years. Then she retired from work and started withdrawing from the account at the rate of `$5000` per year.</p><p>(a) What was the balance of her account `25` years after 1980?</p> <p>(b) What was the balance of her account after `10` more years?</p><p>Round to the nearest hundredth if needed.</p>

<p>Nathan opened an account with `$100`. He deposited `$20` from his pocket money weekly for the next `2 1/2` weeks. Thereafter, he spent `$60` to commute to his college weekly for the following `3` weeks.</p><p>a. What was his account balance after `2 1/2` weeks?</p><p>b. What was her account balance after the following `3` weeks?</p><p>Round to the nearest hundredth if needed.</p>

<p>An investor looked at the price of a stock throughout `2020`.</p><ul><li>The initial price of the stock was `$10`. </li><li>The price of the stock increased at a steady rate of `$30` per month for the first `3 1/2` months of the year.</li> <li>Then, the price fell at the rate of `$10` per month for the next `7` months.</li></ul><p>Questions:</p><ul><li>What was the price of the stock after the first `3 1/2` months?</li><li>What was the price of the stock after the following `7` months?</li></ul><p><highlight data-color="#666" data-style="italic">Round to the nearest hundredth if needed. </highlight></p>

<p>Antarctica's average temperature was recorded over a several months.</p><ul><li>The average temperature for the month of June was `-76°`F. </li><li>For `3` months, the average temperature decreased by `2.5°`F every month. </li><li>Then, for `2` months, the average temperature increased by `12°`F every month.</li></ul><p>Questions: </p><ul><li>What was the average temperature in Antarctica after `3` months?</li><li>What was the average temperature in Antarctica after the following `2` months?</li></ul><p><highlight data-color="#666" data-style="italic">Round to the nearest hundredth if needed. </highlight></p>

<p>A science experiment requires a liquid to be heated up, and then cooled off again. At the start of the experiment, the temperature of the liquid is `-14`°F. The scientist then increases the temperature of the liquid by `7.9`°F per minute for `3.5` minutes. Then, the scientist decreases the temperature of the liquid by `6`°F per minute for `2` minutes.</p><p>a. What was the temperature after `3.5` minutes?</p><p>b. What was the temperature after the following `2` minutes?</p><p>Round to the nearest hundredth if needed.</p>

<p>To make mint-flavored ice cubes, Elijah used a blender to make mint juice and poured the juice into ice cube trays. </p><ul><li>The temperature of the mint juice inside the blender was `24`°C. </li><li>After he put the ice tray inside the freezer, the temperature dropped by `6.5`°C for the first `2` hours. </li><li>He then turned on the blast freeze option of the freezer, and the temperature dropped by `9`°C per hour for the next `3` hours.</li></ul><p>Questions:</p><ul><li>What was the temperature of the mint juice after `2` hours?</li><li>What was the temperature of the mint juice after the following `3` hours?</li></ul><p><highlight data-color="#666" data-style="italic">Round to the nearest hundredth if needed. </highlight></p>

<p>Mary kept track of the changes in her bank balance.</p><ul><li>Mary had an account balance total of `-$24.50` at the beginning of the month. </li><li>She added `$40` per day to her account for the following `12` days. </li><li>Then, for the next `7` days, she took out `$32` each day for travel expenses for work.</li></ul><p>Questions:</p><ul><li>What was her account balance for the next `12` days?</li><li>What was her account balance after the following `7` days?</li></ul><p><highlight data-color="#666" data-style="italic">Round to the nearest hundredth if needed. </highlight></p>