# Thread: Dont understand the explanation

1. ## Dont understand the explanation

When the sale prices of Calir's product line were decreased by 25%, £65,277 in revenues were generated in less than 2 weeks. If the sales ratio of XC to XR units was 3:4 respectively, what is the difference in the number of units sold between the two product types?
 A 5
 B 18
 C 6
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Explanation
Remember that ratios do not represent real numbers. We need to find the multiplication factor which connects us to the real numbers.

Let's look at the entire mathematical expression that represents the data and the solution:

0.75*( 1734*3X + 2326*4X)= £65,277

0.75 is the 25% price reduction that applies on both products.
1734 and 2326 are the prices of XC and XR units, repsectively.
X is the multiplication factor that tells us the real numbers of units sold, in stead of just the ratio. In fact, it is also the difference we're looking for.

Solving this gives us x=6. When applying the multiplication factor to the basic ratio we get:
3*6= 18 units of XC
4*6=24 units of XR
Where does 6 come from???