 Hello and welcome to the session. My name is Mansi. I'm going to help you with the following question. The question says a solution is to be kept between 68 degree Fahrenheit and 77 degree Fahrenheit. What is the range in temperature in degree Celsius? See if the Celsius or Fahrenheit F conversion formula is given by F equals to 9 by 5C plus 32. Let's start with the solution to this question. We see that the Celsius, C or Fahrenheit conversion formula is given by F is equal to 9 by 5C plus 32. Now, since the temperature in which the solution can be kept should be more than 68 degree Fahrenheit but less than 77 degree Fahrenheit, therefore we have the following two inequalities. First is 9 by 5C plus 32 is strictly greater than 68 and second is 9 by 5C plus 32 is strictly less than 77. So we are required to solve them for C. We see that the first inequality is 9 by 5C plus 32 is strictly greater than 68 or 9C plus 160 is strictly greater than 340 or 9C is strictly greater than 180 or C is strictly greater than 20. We also see the second inequality is 9 by 5C plus 32 is strictly less than 77 or 9C plus 160 is strictly less than 385 or 9C is strictly less than 225 or C is strictly less than 25. Hence, 20 is strictly less than C is strictly less than 25. Therefore, required range is between 20 degree Celsius and 25 degree Celsius and this is our answer to this question. I hope you understood the question and enjoyed the session. Have a good day.