Problem: In 2005, the number of pairs of the shoes that a company sold to retailers decreased by 20 percent, while the price per pair increased by 20 percent from that of the previous year. The company’s revenue from the sales of the shoes in 2005 was Tk 300,000. What was the revenue from the sale of the shoes in the previous year?

Correct Answer: In 2004, the amount of revenue was 3,12,500 Tk.

Explanation:

In 2005

At 20% decrease of sale of pair of shoes, present number of sale = 100 – 20 = 80

The revenue from selling of the company will be Tk. = 80 x 100 = 8,000 Tk.

But the actual revenue would be Tk. = 100 x 100 = 10,000

If present revenue is Tk. 8,000 then actual revenue is = 10,000 Tk.

If present revenue is Tk. 1 then actual revenue is = $\frac{10000}{8000}$Tk.

If present revenue is Tk. 300,000 then actual revenue is = $\frac{10000×300000}{8000}$= 375,000 TK

Now, in 2004

At 20% increase, the price of each pair of shoes be = 100 + 20 = 120 Tk.

The revenue from selling of the company will be = (120 x 100) Tk. = 12000 Tk.

lf Tk. 12000 is present sale, then previous sale was = 10000 Tk.

If Tk. 1 is present sale, then previous sale was = $\frac{10000}{12000}$

If ‘Tk. 375,000 is present sale, then previous sale was = $\frac{10000×375000}{12000}$ = 3,12,500 TK