Maths Puzzles

 Solution to puzzle 17: Renaldo has received 3025 as his total money for the month out of which 2500 is salary. Which means he received 525 as commission for his sales. 525 = 10.5% of x x = 525 * 100 /10.5 = 5000 $ His sales for the month was $5000.   Puzzle 18 : Liar Liar Christanio Ronaldo is a strange liar. He lies on six days of the week, but on the seventh day he always tells the truth. He made the following statements on three successive days: Day 1: 'I lie on Monday and Tuesday.' Day 2: 'Today, it's Thursday, Saturday, or Sunday.' Day 3: 'I lie on Wednesday and Friday.' On which day does Christanio Ronaldo tell the truth? 

 Sorry. I am not keeping up for the last few days. I am stuck in an infinite loop of trying to install an IDE on my laptop. Unsuccessfully so far.  Solution to puzzle 16: The product of the ages of 3 sisters is 175 and two of them are twins.  Let us say the age of twins is x. So x^2 y = 175 Now the factors of 175 are 7 , 5 and 25. So y should be 7 and x^2 is 25.  So the age of the third girl is 7. Puzzle 17: This puzzle is pure maths and hence will be easier to solve.     Each month, Renaldo earns a commission of 10.5% of his total sales for the month, plus a salary of $2,500. If Renaldo earns $3,025 in a certain month, what were his total sales?