MATH 6 QUARTER 2 WEEK 4 | SOLVING PERCENT PROBLEMS

This lesson focuses on solving percent problems in Math 6, addressing topics such as percent of increase or decrease (discounts, original price, rate of discount, sale price, markup price, commission, sales tax, and simple interest). The video will cover applying learned concepts in finding percentage, rate, and base.

The video defines key terms for discount problems: Discount (D) is the decrease in price, Original Price (OP) is the regular price, Discount Rate (DR) is the percentage taken off, and Sale Price (SP) is the discounted price. Discount and sale price represent percentages, while original price is the base and discount rate is the rate.

A dress sold for 500 pesos at a 16% discount. To find the discount (D), use D = DR * OP. D = 16% * 500 pesos = 0.16 * 500 pesos = 80 pesos. To find the sale price (SP), use SP = OP - D. SP = 500 pesos - 80 pesos = 420 pesos.

A wristwatch sold for 2,500 pesos with a 20% discount. To find the original price (OP), use SP = OP * (100% - DR). 2,500 pesos = OP * (100% - 20%). 2,500 pesos = OP * 0.80. OP = 2,500 pesos / 0.80 = 3,125 pesos.

Markup (M) is an increase in price for profit. Markup Rate (MR) is the percent added to the cost. Cost (C) is the original amount. Markup and selling price represent percentages, cost is the base, and markup rate is the rate.

A businesswoman adds a 4.50 peso markup on plastic products with a cost of 50 pesos. To find the markup rate (MR), use MR = (M / C) * 100%. MR = (4.50 pesos / 50 pesos) * 100% = 0.09 * 100% = 9%. To find the selling price (SP), use SP = C + M. SP = 50 pesos + 4.50 pesos = 54.50 pesos.

Commission (C) is an amount received for selling, Total Sales (TS) is the total amount sold, Commission Rate (CR) is the percent taken from the selling price, and Sale Proceeds (SP) is the amount remaining after commission. Commission and sale proceeds are percentages, total sales is the base, and commission rate is the rate.

Mr. Lazo receives an 8% commission on a car sold for 1,550,000 pesos. To find commission (C), use C = TS * CR. C = 1,550,000 pesos * 8% = 1,550,000 pesos * 0.08 = 124,000 pesos. To find sale proceeds (SP), use SP = TS - C. SP = 1,550,000 pesos - 124,000 pesos = 1,426,000 pesos.

Mr. Lazo was given 120,000 pesos as a 6% commission for selling a house and lot. To find the total sales (TS), use TS = C / CR. TS = 120,000 pesos / 6% = 120,000 pesos / 0.06 = 2,000,000 pesos.

Sales tax is an added tax on products. To find sales tax, use Sales Tax = Total Product Amount * Rate of Sales Tax. To find the total amount paid, add the sales tax to the total product amount.

A family ordered food totaling 856 pesos with a 12% sales tax. Sales tax = 856 pesos * 12% = 856 pesos * 0.12 = 102.72 pesos. Total amount paid = 856 pesos + 102.72 pesos = 958.72 pesos.

Interest (I) is money earned for using another's money. Principal (P) is the amount deposited or borrowed. Rate of Interest (R) is the percent added. Time (T) is the length of time (in years). Amount Due (AD) is the total amount paid or received.

Mr. Lazo has 9,500 pesos in a savings account earning 1.5% interest per year. To find the interest (I), use I = P * R * T. I = 9,500 pesos * 1.5% * 1 year = 9,500 pesos * 0.015 * 1 = 142.50 pesos.

Deo Lario borrowed money at 6% interest, paying 450 pesos interest after 19 months. To find the principal (P), use P = I / (R * T). Convert 19 months to years (1.7 years). P = 450 pesos / (6% * 1.7) = 450 pesos / (0.06 * 1.7) = 450 pesos / 0.102 = 4,411.76 pesos. The given answer 5000 pesos appears to be a rounding or calculation discrepancy in the video's solution. Re-calculation of the provided example is 450 pesos / (0.06 * (19/12)) = 450 pesos / 0.095 = 4736.84 pesos. The video's step 0:18:33 calculation of 0.06 * 1.7 = 0.102 is correct, but then in the next step, 450 / 0.102 is stated to be 5000. 450 / 0.102 = 4411.76. The number 5000 is produced by a much smaller divisor, such as 0.09.

The video presents a series of practice problems to be solved, covering discounts, sale prices, markup prices, selling prices, commission, total sales, simple interest, and interest rates. Each problem is worked through illustrating the formulas and calculations demonstrated earlier.

The video continues with a series of word problems, instructing the viewer to solve them by applying the learned formulas for discount, sale price, original price, sales tax rate, and other percentage-related calculations. Solutions are provided for the first few problems, and the remaining problems are left for the viewer to practice independently.