CAT
Concept Session 1: Ratio, Proportion and Variation
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Session 1
Ratio – Introduction and Terminology
Ratio - Properties
Combining ratios
Proportion – Properties
Session 2
Variation – Properties
Comparison of fractions – Part 1
Comparison of fractions – Part 2
Problem Set – 1
Problem Set -2
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Ratio, Proportion and variation
Ratio, Proportion and Variation – Session 1
• Ratio – Introduction and Terminology
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Ratio – What is it?
 Ratio: Comparison of magnitude of two quantities.
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The ratio of the expenses of A and B is 5:9. If the sum of their
expenses is Rs. 28000.
- What is A’s expense?
- By how much is B’s expense greater than A’s expense?
Ratio – Problems on basic understanding
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What is the value of A:B:C ? If,
a) A:B:C =
1
3
∶
1
2
∶
1
5
b)
A
3
=
B
2
=
C
5
Ratio – Terminology
 Terminology
 Antecedent and consequent
 Let the ratio of A’s age and B’s age = a:b and B’s age and C’s age = b:c
 Duplicate ratio of their ages =
 Triplicate ratio of their ages =
 Sub-duplicate ratio of their ages =
 Sub-triplicate ratio of their ages =
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Ratio – Terminology
⁻ If 5a+2 : 12a+4 is the triplicate ratio of 3:4, what is the value of a?
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Ratio, Proportion and Variation – Session 1
• Ratio – Properties
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Ratio – Properties
Properties of Ratios
Value of ratios when multiplied or divided by the same number remains the
same
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Ratio – Properties
Properties of Ratios
Change of values of proper and improper fractions when the same value is added or subtracted
to the Nr and the Dr.
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Proper Fraction Improper Fraction
Ratio – Properties
Properties of Ratios
If
𝑎
𝑏
=
𝑐
𝑑
=
𝑒
𝑓
……. then
𝑎 + 𝑐 + 𝑒 +⋯
𝑏+𝑑+𝑓+⋯
= each of
𝑎
𝑏
,
𝑐
𝑑
… As long as (𝑏 +
𝑑 + 𝑓 + ⋯ ) ≠ 0
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Ratio – Properties
Properties of Ratios
• Given
𝑎
𝑏
,
𝑐
𝑑
,
𝑒
𝑓
, the value of
𝑎+𝑐+𝑒
𝑏+𝑑+𝑓
will be between the lowest and highest fraction.
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Ratio – Properties
Properties of Ratios - Summary
• Value of ratios when multiplied or divided by the same number remains the
same
• Change of values of proper and improper fractions when the same value is
added or subtracted to the Nr and the Dr.
• If
𝑎
𝑏
=
𝑐
𝑑
=
𝑒
𝑓
……. then
𝑎 + 𝑐 + 𝑒 +⋯
𝑏+𝑑+𝑓+⋯
= each of
𝑎
𝑏
,
𝑐
𝑑
… As long as (𝑏 + 𝑑 + 𝑓 + ⋯ ) ≠
0
• Given
𝑎
𝑏
,
𝑐
𝑑
,
𝑒
𝑓
, the value of
𝑎+𝑐+𝑒
𝑏+𝑑+𝑓
will be between the lowest and highest fraction.
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Ratio – Properties
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If
𝑎+𝑏
𝑐
=
𝑏+𝑐
𝑎
=
𝑎+𝑐
𝑏
= p, what is the value of p?
1) 2 2) -1 3) -2 4) Either 1) or 2)
Ratio, Proportion and Variation – Session 1
• Combining Ratios
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Ratio – Combining ratios
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Ratio – Problems
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If A:B = 3:1, C:B = 2:1, C:D = 1:3 what is the value of A:D?
1) 1:2 2) 2:1 3) 1:3 4) None of these
Ratio – Problems
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A has thrice the amount of money that B has, B has twice
the amount of money that C has and thrice the amount of
money with C is equal to four times the amount of money
with D. The amount of money with D is what percentage of
the amount of money with A?
1) 200 2) 25 3) 12.5 4) None of these
Ratio, Proportion and Variation – Session 1
• Proportion – Properties
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Proportion – What is it?
 What is a proportion?
 Product of extremes = product of means
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Proportion – Continued Proportion
 If a:b =b:c, then a,b and c are in continued proportion.
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Proportion – Properties
 Invertendo
 Alternendo
 Componendo
 Dividendo
 Componendo-dividendo
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Proportion – Problems
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Ratio of p:q is the same as that of q:r, where p, q and r are
positive numbers. If p = 16 and r = 100, find q.
1) 40 2) 64 3) 24 4) None of these
Proportion – Problems
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Find the fourth proportional to 1, 3 and 4
1) 12 2) 24 3) 18 4) None of these

Rpv session 1

  • 1.
    CAT Concept Session 1:Ratio, Proportion and Variation www.georgeprep.com 9985-372-371
  • 2.
    Session 1 Ratio –Introduction and Terminology Ratio - Properties Combining ratios Proportion – Properties Session 2 Variation – Properties Comparison of fractions – Part 1 Comparison of fractions – Part 2 Problem Set – 1 Problem Set -2 www.georgeprep.com 9985-372-371 Ratio, Proportion and variation
  • 3.
    Ratio, Proportion andVariation – Session 1 • Ratio – Introduction and Terminology www.georgeprep.com 9985-372-371
  • 4.
    Ratio – Whatis it?  Ratio: Comparison of magnitude of two quantities. www.georgeprep.com 9985-372-371 The ratio of the expenses of A and B is 5:9. If the sum of their expenses is Rs. 28000. - What is A’s expense? - By how much is B’s expense greater than A’s expense?
  • 5.
    Ratio – Problemson basic understanding www.georgeprep.com 9985-372-371 What is the value of A:B:C ? If, a) A:B:C = 1 3 ∶ 1 2 ∶ 1 5 b) A 3 = B 2 = C 5
  • 6.
    Ratio – Terminology Terminology  Antecedent and consequent  Let the ratio of A’s age and B’s age = a:b and B’s age and C’s age = b:c  Duplicate ratio of their ages =  Triplicate ratio of their ages =  Sub-duplicate ratio of their ages =  Sub-triplicate ratio of their ages = www.georgeprep.com 9985-372-371
  • 7.
    Ratio – Terminology ⁻If 5a+2 : 12a+4 is the triplicate ratio of 3:4, what is the value of a? www.georgeprep.com 9985-372-371
  • 8.
    Ratio, Proportion andVariation – Session 1 • Ratio – Properties www.georgeprep.com 9985-372-371
  • 9.
    Ratio – Properties Propertiesof Ratios Value of ratios when multiplied or divided by the same number remains the same www.georgeprep.com 9985-372-371
  • 10.
    Ratio – Properties Propertiesof Ratios Change of values of proper and improper fractions when the same value is added or subtracted to the Nr and the Dr. www.georgeprep.com 9985-372-371 Proper Fraction Improper Fraction
  • 11.
    Ratio – Properties Propertiesof Ratios If 𝑎 𝑏 = 𝑐 𝑑 = 𝑒 𝑓 ……. then 𝑎 + 𝑐 + 𝑒 +⋯ 𝑏+𝑑+𝑓+⋯ = each of 𝑎 𝑏 , 𝑐 𝑑 … As long as (𝑏 + 𝑑 + 𝑓 + ⋯ ) ≠ 0 www.georgeprep.com 9985-372-371
  • 12.
    Ratio – Properties Propertiesof Ratios • Given 𝑎 𝑏 , 𝑐 𝑑 , 𝑒 𝑓 , the value of 𝑎+𝑐+𝑒 𝑏+𝑑+𝑓 will be between the lowest and highest fraction. www.georgeprep.com 9985-372-371
  • 13.
    Ratio – Properties Propertiesof Ratios - Summary • Value of ratios when multiplied or divided by the same number remains the same • Change of values of proper and improper fractions when the same value is added or subtracted to the Nr and the Dr. • If 𝑎 𝑏 = 𝑐 𝑑 = 𝑒 𝑓 ……. then 𝑎 + 𝑐 + 𝑒 +⋯ 𝑏+𝑑+𝑓+⋯ = each of 𝑎 𝑏 , 𝑐 𝑑 … As long as (𝑏 + 𝑑 + 𝑓 + ⋯ ) ≠ 0 • Given 𝑎 𝑏 , 𝑐 𝑑 , 𝑒 𝑓 , the value of 𝑎+𝑐+𝑒 𝑏+𝑑+𝑓 will be between the lowest and highest fraction. www.georgeprep.com 9985-372-371
  • 14.
    Ratio – Properties www.georgeprep.com9985-372-371 If 𝑎+𝑏 𝑐 = 𝑏+𝑐 𝑎 = 𝑎+𝑐 𝑏 = p, what is the value of p? 1) 2 2) -1 3) -2 4) Either 1) or 2)
  • 15.
    Ratio, Proportion andVariation – Session 1 • Combining Ratios www.georgeprep.com 9985-372-371
  • 16.
    Ratio – Combiningratios www.georgeprep.com 9985-372-371
  • 17.
    Ratio – Problems www.georgeprep.com9985-372-371 If A:B = 3:1, C:B = 2:1, C:D = 1:3 what is the value of A:D? 1) 1:2 2) 2:1 3) 1:3 4) None of these
  • 18.
    Ratio – Problems www.georgeprep.com9985-372-371 A has thrice the amount of money that B has, B has twice the amount of money that C has and thrice the amount of money with C is equal to four times the amount of money with D. The amount of money with D is what percentage of the amount of money with A? 1) 200 2) 25 3) 12.5 4) None of these
  • 19.
    Ratio, Proportion andVariation – Session 1 • Proportion – Properties www.georgeprep.com 9985-372-371
  • 20.
    Proportion – Whatis it?  What is a proportion?  Product of extremes = product of means www.georgeprep.com 9985-372-371
  • 21.
    Proportion – ContinuedProportion  If a:b =b:c, then a,b and c are in continued proportion. www.georgeprep.com 9985-372-371
  • 22.
    Proportion – Properties Invertendo  Alternendo  Componendo  Dividendo  Componendo-dividendo www.georgeprep.com 9985-372-371
  • 23.
    Proportion – Problems www.georgeprep.com9985-372-371 Ratio of p:q is the same as that of q:r, where p, q and r are positive numbers. If p = 16 and r = 100, find q. 1) 40 2) 64 3) 24 4) None of these
  • 24.
    Proportion – Problems www.georgeprep.com9985-372-371 Find the fourth proportional to 1, 3 and 4 1) 12 2) 24 3) 18 4) None of these