A family of four had dinner together at a restaurant. Write two expressions for calculating their total bill if they leave a 15% tip. Let c represent the cost of their meal before tipping.

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.