from the informations given in the question;
[tex]\begin{gathered} \text{Let } \\ nu\text{mber of customers who enter the store last w}eek\text{ = x} \end{gathered}[/tex]since 25% of their weekly customers would purchase a new R- phone before leaving the store and this was equivalent to 75 customers
then we have
[tex]25\text{\% 0f x = 75}[/tex]hence we need to solve for x
[tex]\begin{gathered} 25\text{\% of x =75} \\ \text{implies} \\ \frac{25}{100}\text{ }\times\text{ x = 75} \\ \frac{1}{4}\text{ }\times\text{ x = 75} \\ \frac{x}{4}\text{ = 75 } \\ \text{cross multiply} \\ x\text{ = 4 x 75} \\ x\text{ = 300} \end{gathered}[/tex]therefore
the number of customers that enter the store last week is 300 customers
