If $5\%$ of people that see your ad, click on it and go to your website, $6\%$ of those that click buy $1$ product, and $3\%$ of those who click buy $2$ products.
how many people need to see the ad, in order to sell $7500$ products?
I don't know how what kind of equations I should build.
First one is:
$C = P\times0.05 (5\%$ of people P turn to Clickers C)
But Second one, I'm not sure:
$X_1 =C\times0.06 (6 \%$ of Clickers C, turns into X unit sold)
$X_2 =C\times0.03 (3 \%$ of Clickers C, turns into 2X unit sold)
and $X_2 = 2\times X_1$ (Two times X units sold are one time 2X units are sold)
and we require that 7500 units will be sold, and they are composed from $X_2$ and $X_1$ so:
$7500 = X_1+X_2$
And to take everything:
$7500=3\times X_1$
$X_1 = 2500$
$2500 = 0.06\times C$ $C= 41,666,666$ $P = 833,333.33$
But it doesn't make sense. Answer should be $1,250,000$
Let total number of people be $x$ .
People who see your ad : $\dfrac{5x}{100}$
People who buy one product : $\dfrac{5x}{100} \times \dfrac6{100} = \dfrac{3x}{1000}$
People who buy two products : $\dfrac{3x}{2000}$.
According to the question :
$$\dfrac{3x}{1000} + 2\times\dfrac{3x}{2000} = 7500$$
Can you complete the rest ?