Republic of the Philippines
Department of Education
San Rafael National High School
Senior High School

Quiz: Give the function that can represent the following situations.

1. A person is earning [tex]$750.00 per day to do a certain job. Express the total salary \( S \) as a function of the number \( n \) of days that the person works.

2. A computer shop charges $[/tex]15.00 per hour of computer rental. Represent your computer rental fee ([tex]\( R \)[/tex]) using the function [tex]\( R(t) \)[/tex], where [tex]\( t \)[/tex] is the number of hours you spent on the computer.

3. A parking fee at SM Lucena costs [tex]$25.00 for the first two hours and an extra $[/tex]5.00 for each additional hour. If you park for more than twelve hours, you pay a flat rate of $100.00. Represent your parking fee using the function [tex]\( p(t) \)[/tex], where [tex]\( t \)[/tex] is the number of hours you parked in the mall.

Grade 11 General Mathematics - Functions and Their Graphs



Answer :

Certainly! Let's carefully break down each situation to define the appropriate functions:

1. Total salary as a function of the number of days worked:

- Situation: A person earns [tex]$750 per day. - Function Definition: Let \( S(n) \) be the total salary where \( n \) is the number of days worked. - Function: \[ S(n) = 750n \] This means that the total salary \( S(n) \) is 750 multiplied by the number of days \( n \). 2. Computer rental fee as a function of the hours spent: - Situation: A computer shop charges $[/tex]15 per hour.
- Function Definition: Let [tex]\( R(t) \)[/tex] be the computer rental fee where [tex]\( t \)[/tex] is the number of hours spent.
- Function:
[tex]\[ R(t) = 15t \][/tex]
This means that the rental fee [tex]\( R(t) \)[/tex] is 15 multiplied by the number of hours [tex]\( t \)[/tex].

3. Parking fee as a function of the hours parked:

- Situation: The parking fee is [tex]$25 for the first 2 hours and an additional $[/tex]5 for each hour beyond that. If the time parked exceeds 12 hours, a flat rate of [tex]$100 applies. - Function Definition: Let \( p(t) \) be the parking fee where \( t \) is the number of hours parked. - Function: \[ p(t) = \begin{cases} 25 & \text{if } t \leq 2 \\ 25 + 5(t - 2) & \text{if } 2 < t \leq 12 \\ 100 & \text{if } t > 12 \end{cases} \] This function \( p(t) \) accounts for the different charges based on the hours parked: a flat $[/tex]25 for up to 2 hours, an additional [tex]$5 per hour for more than 2 but up to 12 hours, and a flat $[/tex]100 for more than 12 hours.

To summarize, the functions for each situation are:
1. [tex]\( S(n) = 750n \)[/tex]
2. [tex]\( R(t) = 15t \)[/tex]
3. [tex]\[ p(t) = \begin{cases} 25 & \text{if } t \leq 2 \\ 25 + 5(t - 2) & \text{if } 2 < t \leq 12 \\ 100 & \text{if } t > 12 \end{cases} \][/tex]