University:
Montgomery College
Course:
MATH 130: Elements of Mathematics I: Mathematical Reasoning and Number Systems
Academic year:

2023
Views:

56

Pages:

1
Author:

jaxbrokenhart4z4x

Mini-Lecture 2.7 Percent and Mixture Problem Solving Learning Objectives: 1. 2. 3. 4. Solve percent equations. Solve discount and mark-up problems. Solve percent increase and percent decrease problems. Solve mixture problems. Examples: 1. Find each number described. a) 5% of 300 is what number? c) 15 is 1% of what number? b) 207 is 90% of what number? d) What percent of 350 is 420? 2. Solve the following discount and mark-up problems. If needed, round answers to the nearest cent. a) A “Going-Out-Of-Business” sale advertised a 75% discount on all merchandise. Find the discount and the sale price of an item originally priced at $130. b) Recently, an anniversary dinner cost $145.23 excluding tax. Find the total cost if a 15% tip is added to the cost. 3. Solve the following percent increase and decrease problems. a) The number of minutes on a cell phone bill went from 1200 minutes in March to1600 minutes in April. Find the percent increase. Round to the nearest whole percent. b) In 2004, a college campus had 8,900 students enrolled. In 2005, the same college campus had 7,600 students enrolled. Find the percent decrease. Round to the nearest whole percent. c) Find the original price of a pair of boots if the sale price is $120 after a 20% discount. 4. How much pure acid should be mixed with 4 gallons of a 30% acid solution in order to get a 80% acid solution? Use the following table to model the situation. Number of Gallons · Acid Strength = Amount of Acid Pure Acid 30% Acid Solution 80% Acid Solution Needed Teaching Notes: • • Most students find problem solving challenging. Encourage students to make a list of all appropriate formulas. Each section in the text has 3 worksheets in the Extra Practice featuring differentiated learning. Answers: 1a) 15; 1b) 230; 1c) 1500; 1d) 120%; 2a) discount - $97.50, sale price - $32.50; 2b) $167.01; 3a) 33%; 3b) 15%; 3c) $150; 4) 10 gallons