View
220
Download
2
Category
Tags:
Preview:
Citation preview
Sec 3.5 Increase and Decrease Sec 3.5 Increase and Decrease ProblemsProblems
• Objectives–Learn to identify an increase or
decrease problem.
–Apply the basic diagram for increase or decrease problems.
–Use the basic percent formula to solve increase or decrease problems.
Increase ProblemsIncrease Problems
The part equals 100% of the base plus some portion of the base.
Increase ProblemsIncrease Problems
The part equals 100% of the base plus some portion of the base.
Phrases such as after an increase of,
Increase ProblemsIncrease Problems
The part equals 100% of the base plus some portion of the base.
Phrases such as after an increase of, more than,
Increase ProblemsIncrease Problems
The part equals 100% of the base plus some portion of the base.
Phrases such as after an increase of, more than, or greater than
Increase ProblemsIncrease Problems
The part equals 100% of the base plus some portion of the base.
Phrases such as after an increase of, more than, or greater than often indicate an increase problem.
Increase ProblemsIncrease Problems
The part equals 100% of the base plus some portion of the base.
Phrases such as after an increase of, more than, or greater than often indicate an increase problem.
The basic formula for an increase problem is:
Increase ProblemsIncrease Problems
The part equals 100% of the base plus some portion of the base.
Phrases such as after an increase of, more than, or greater than often indicate an increase problem.
The basic formula for an increase problem is:
Original value + Increase = New Value
Example 1Example 1
Base Rate of Part
Inc. (after Inc.)
???? 20% $660
Base plus some portion of the base equals $660.
Base
????
Base
????
Amt. Of Increase
Base
????
Amt. Of Increase
20% of Base
Base
????
Amt. Of Increase
20% of Base
Sum of Base
and increase is
$660
Part Rate of Base
(after Inc.) Inc.
$660 20% ???
100% of Base + 20% of Base = $660
100% of Base + 20% of Base = $660
120% of Base = $660
100% of Base + 20% of Base = $660
120% of Base = $660
R x B = P
100% of Base + 20% of Base = $660
120% of Base = $660
R x B = P
Hence, R = 120%
P = $660
B = ???
R x B = PHence, R = 120% P = $660 B = ??? Thus, P $660 $660B = ----- = ---------- = ----------- = $550 R 120% 1.2
So if we take 100% of the base ($550) + 20% of the base ($110) we get $660 (part).
Decrease ProblemsDecrease Problems
The part equals 100% of the base minus some portion of the base.
Decrease ProblemsDecrease Problems
The part equals 100% of the base minus some portion of the base.
Phrases such as after a decrease of,
Decrease ProblemsDecrease Problems
The part equals 100% of the base minus some portion of the base.
Phrases such as after a decrease of, less than,
Decrease ProblemsDecrease Problems
The part equals 100% of the base minus some portion of the base.
Phrases such as after a decrease of, less than, or after a reduction of
Decrease ProblemsDecrease Problems
The part equals 100% of the base minus some portion of the base.
Phrases such as after a decrease of, less than, or after a reduction of often indicate a decrease problem.
Decrease ProblemsDecrease Problems
The part equals 100% of the base minus some portion of the base.
Phrases such as after a decrease of, less than, or after a reduction of often indicate a decrease problem.
The basic formula for a decrease problem is:
Decrease ProblemsDecrease Problems
The part equals 100% of the base minus some portion of the base, yielding a new value.
Phrases such as after a decrease of, less than, or after a reduction of often indicate a decrease problem.
The basic formula for a decrease problem is:
Original Value - Decrease = New Value
ExampleExample 2 2
The sale price of a new Palm Pilot, after a 15% decrease, was $98.38. Find the price of the Palm Pilot before the decrease.
ExampleExample 2 2
Base Rate of Part Dec. (after Dec.)
??? 15% $98.38
Base minus some portion of the base equals $98.38.
Price Paid = $98.38
(Part)
Price Paid = $98.38
(Part)
Amt. of Decrease
Price Paid = $98.38
(Part)
Amt. of Decrease
15% of Base
Price Paid = $98.38
(Part)
Amt. of Decrease
15% of Base
Orig. Price minus decrease = price paid
Base Rate of Part Dec. (after Dec.)
??? 15% $98.38
100% of Base - 15% of Base = $98.38
100% of Base - 15% of Base = $98.38
85% of Base = $98.38
85% of Base = $98.38
R x B = P
85% of Base = $98.38
R x B = P
Hence, R = 85%
P = $98.38
B = ???
85% of Base = $98.38
R x B = P
Hence, R = 85%
P = $98.38
B = ???
Thus,
P $98.38 $98.38
B = ----- = ---------- = ----------- = $115.74
R 85% 0.85
So, if we take 100% of the base ($115.74) minus 15% of the base ($17.36) we get $98.38.
Homework Sec 3.5: 1, 3, 5, 7, …, 33Homework Sec 3.5: 1, 3, 5, 7, …, 33
Recommended