Rita baked 3 tomes as many chocolate cookies as butter cookies. After selling 60 chocolate cookies and 12 butter cookies, there were 3 times as many butter cookies as chocolate cookies. How many chocolate cookies did Rita bake at first?
Q. Rita baked 3 tomes as many chocolate cookies as butter cookies. After selling 60 chocolate cookies and 12 butter cookies, there were 3 times as many butter cookies as chocolate cookies. How many chocolate cookies did Rita bake at first?
Define Variables: Let the number of butter cookies be b. Then, the number of chocolate cookies is 3b, since Rita baked 3 times as many chocolate cookies as butter cookies.
Calculate Remaining Cookies: After selling 60 chocolate cookies and 12 butter cookies, Rita has 3b−60 chocolate cookies and b−12 butter cookies left.
Set Up Equation: According to the problem, after selling the cookies, there were 3 times as many butter cookies as chocolate cookies. So, we can write the equation: b−12=3(3b−60).
Solve Equation: Now, we solve the equation: b−12=9b−180.
Combine Like Terms: Bring all the b terms to one side: b−9b=−180+12.
Simplify Equation: Simplify the equation: −8b=−168.
Find Value of b: Divide both sides by −8 to find the value of b: b=−8−168.
Calculate Number of Chocolate Cookies: Calculate the value of b: b=21.
Calculate Number of Chocolate Cookies: Calculate the value of b: b=21.Now that we know the number of butter cookies, we can find the initial number of chocolate cookies, which is 3 times b: 3×21=63 chocolate cookies.