AboutJosh Expertise When I work through problems, I emphasize principles and key ideas which I believe are worth noting. I will try to answer questions in the following areas, but not at the advanced level. Algebra. Sequences & Series. Trigonometry. Functions & Graphs. Coordinate Geometry. Quadratic Polynomials. Exponentials & Logarithms. Basic Calculus. Probability, Permutations and Combinations. Mathematical Induction. Complex numbers. Physics problems.
Experience
Experience: I have worked as a teaching assistant in college. My hope is that more people will share knowledge without boundary, give help without seeking recognition or monetary rewards.
Supplementary Website: See a selection of past questions in my maths repository under "Question Archive"
Education Credentials: Bachelor degree in Engineering Science."Everyone struggles with something."
Question Last year Department store X had a sales total for December that was 4 times the average(arithmetic mean) of the monthly sales totals for January through November. Find the ratio of December sale to total sale for that year.
Answer Shruti,
The sale for that year consists of two parts:
1) Let A represents sales total for January to November.
2) Let B represents sales for December only.
If B=4A, then the ratio of Dec sale to total sale is given by B/(A+B) ....[1]
As A=B/4, substituting this into equation [1], we get B/((5/4)B) = 4/5 after cancellation.
