Expression of total bill is t = 1.15c where t represents total bill and c represents cost of the meal before tipping.
Solution:
Given that family of four had dinner together at restaurant.
Percentage of tip left by family = 15%
Cost of the meal before tipping is represented by variable c.
Need to determine expression for total bill paid.
Let’s assume total bill be represented by variable t.
total bill = cost of the meal before tipping + 15% of tip
15% of tip means 15% of cost of meal before tipping.
=> Total bill = cost of the meal before tipping + 15% of cost of meal before tipping.
On substituting given variable c and assumed variable t in above expression, we get
t = c + 15% of c
[tex]\begin{array}{l}{\Rightarrow t=c+\frac{15}{100} c} \\\\ {\Rightarrow t=\frac{100 c+15 c}{100}=\frac{115 c}{100}} \\\\ {\Rightarrow t=1.15 \mathrm{c}}\end{array}[/tex]
Hence required expression of total bill is t = 1.15c where t represents total bill and c represents cost of the meal before tipping.