The swimming pool is open when the high temperature is higher than 20 ºC. Lainey tried to swim on Monday and Thursday (which was days 3 later). The pool was open on Monday, but it was closed on Thursday. The high temperature was 30 ºC on Monday, but decreased at a constant rate in the next 3 days. Write an inequality to determine the rate of temperature decrease in degrees Celsius per day, d, from Monday to Thursday

Question

The swimming pool is open when the high temperature is higher than 20 ºC. Lainey tried to swim on Monday and Thursday (which was days 3 later). The pool was open on Monday, but it was closed on Thursday. The high temperature was 30 ºC on Monday, but decreased at a constant rate in the next 3 days. Write an inequality to determine the rate of temperature decrease in degrees Celsius per day, d, from Monday to Thursday

Bytelearn · Accepted Answer

Given Information: We know the high temperature on Monday was 30 ºC. Since the pool was closed on Thursday, the temperature must have been 20 ºC or lower. We need to find the rate of temperature decrease over 3 days.Rate of Decrease: Let's denote the rate of temperature decrease per day as d degrees Celsius. The temperature decreased for 3 days, so the total decrease is 3d degrees Celsius.Inequality Setup: We can set up an inequality to represent the situation. The temperature on Monday was 30 ºC, and after decreasing for 3 days, it was at most 20 ºC on Thursday. So, the inequality is: 30 - 3d ≤ 20Solving the Inequality: Now, we solve the inequality for d. Subtract 30 from both sides to isolate the term with d: -3d ≤ 20 - 30 -3d ≤ -10Final Result: To find the value of d, we divide both sides by -3. Remember that dividing by a negative number reverses the inequality sign: d ≥ -10 / -3 d ≥ 10/3Conclusion: The rate of temperature decrease per day, d, must be at least 10/3 degrees Celsius to go from 30 ºC on Monday to 20 ºC or lower by Thursday.

Full solution

More problems from Percent of change: word problems

Related topics