Which expression represent the length of side cd

Plz answer asap! i will reward brainliest and 12 points for these three questions!take notice: these three questions are completely different! 1) what is the percentage of sugar in the syrup made of 10 kg of water and 4 kg of suugar? 2) what was the original price if after 10% discount it became $450? 3) at first a price was decreased by 12%, then it was disounted again by an additional 5%. what is the percent of the total discount? , and remeber i will award brainliest and 12 points!

The mean average cost of standard room per night at a hostel is ? 20.60. therefore, how much does a standard room cost per night at night-time rest days?

20 points + brainliest answer + my mom’s chocolate chip cookie ! subtract.