Question

1. The number of units of a certain item sold by a company in 2010 was 20% higher than the
number of units it sold in 2009. If the number of units of the item sold in 2009 was 3,000
less than that in 2010, how many units did the company sell in 2009?
A. 12,000
B. 15,000
C. 16,000
D. 18,000
E 24,000​

Answer 1

Given:

Number of units sold by a company in 2010 was 20% higher than that of 2009.

Number of units sold in 2009 was 3,000 less than that in 2010.

To find:

Number of units sold in 2009 ?

Solution:

Let number of units sold in 2009 = $x$

Let number of units sold in 2010 = $y$

As per the question statement:

$y$ = 20% higher than $x$

$\Rightarrow y = x + x \times \dfrac{20}{100}\\\Rightarrow y =x+\dfrac{1}{5}x\\\Rightarrow y = \dfrac{6x}{5} ....... (1)$

and

$x =y -3000 ...... (2)$

Putting value of y as per equation (1) in equation (2):

$x =\dfrac{6}{5}x -3000 \\\Rightarrow 3000 =\dfrac{6}{5}x -x\\\Rightarrow \dfrac{1}{5}x = 3000\\\Rightarrow x = 15000$

and $x$ is the number of units sold in 2009 so answer is:

Option B: 15,000