Revision and Self Assessment on Index Numbers Class 11 OP Malhotra Exe-30C ISC Maths Solutions Ch-30. In this article you would learn to solve conceptional problems easily on Index Numbers. Step by step solutions of latest textbook has been given as latest syllabus. Visit official Website CISCE for detail information about ISC Board Class-11.

Index Numbers Class 11 OP Malhotra Revision and Self Assessment ISC Maths Solutions Ch-30
| Board | ICSE |
| Publications | S Chand |
| Subject | Maths |
| Class | 11th |
| Chapter-30 | Index Numbers |
| Writer | OP Malhotra |
| Exe-30(C) | Revision and Self Assessment. |
Revision and Self Assessment on Index Numbers
OP Malhotra ISC Class 11 Maths Solutions
Que-1: Construct the consumer price index number for 1990, taking 1989 as the base year and using simple average of price relative method for the following data:
| Commodities | Price in 1989 | Price in 1990 |
|---|---|---|
| Butter | 20 | 21 |
| Cheese | 16 | 12 |
| Milk | 3 | 3 |
| Egg | 2.80 | 2.80 |
Sol: We use the formula of simple average of price relatives:
Price Relative (P) = (Price in current year / Price in base year) × 100
Now calculate for each commodity:
Butter: (21 / 20) × 100 = 105
Cheese: (12 / 16) × 100 = 75
Milk: (3 / 3) × 100 = 100
Egg: (2.80 / 2.80) × 100 = 100
Now take average:
CPI = (105 + 75 + 100 + 100) / 4
= 380 / 4 = 95
Hence, Consumer Price Index for 1990 = 95
Que-2: A small industrial concern used three raw materials A, B and C in its manufacturing process, the prices of the materials was as shown below.
| Commodity | Price (₹) in 1995 | Price (₹) in 2005 |
|---|---|---|
| A | 4 | 5 |
| B | 60 | 57 |
| C | 36 | 42 |
Using 1995 as the base year, calculate a simple aggregate price index for 2005.
Sol: We use the simple aggregate price index formula:
Price Index = (ΣP₁ / ΣP₀) × 100
Where:
P₀ = Price in base year (1995)
P₁ = Price in current year (2005)
Now calculate sums:
ΣP₀ = 4 + 60 + 36 = 100
ΣP₁ = 5 + 57 + 42 = 104
Now substitute:
Price Index = (104 / 100) × 100 = 104
Hence, Simple Aggregate Price Index for 2005 = 104
Que-3: Find the consumer price index number for the year 2010 as the base year by using method of weighted aggregates.
| Commodity | A | B | C | D | E |
|---|---|---|---|---|---|
| Year 2000 price (₹) per unit | 16 | 40 | 0.50 | 5.12 | 2.00 |
| Year 2010 price (₹) per unit | 20 | 60 | 0.50 | 6.25 | 1.50 |
| Weights | 40 | 25 | 5.00 | 20.00 | 10.00 |
Sol: We are given data for base year (2000) and current year (2010) along with weights.
We need to find Consumer Price Index (CPI) using Weighted Aggregative Method.
Formula:
CPI = (Σ W × P₁ / Σ W × P₀) × 100
Where,
P₀ = Price in base year (2000)
P₁ = Price in current year (2010)
W = Weights
Now calculate W × P₀ and W × P₁:
| Commodity | W | P₀ | P₁ | W × P₀ | W × P₁ |
|---|---|---|---|---|---|
| A | 40 | 16 | 20 | 640 | 800 |
| B | 25 | 40 | 60 | 1000 | 1500 |
| C | 5 | 0.50 | 0.50 | 2.5 | 2.5 |
| D | 20 | 5.12 | 6.25 | 102.4 | 125 |
| E | 10 | 2.00 | 1.50 | 20 | 15 |
| Total | 1764.9 | 2442.5 |
Now apply formula : CPI = (2442.5 / 1764.9) × 100
CPI ≈ 138.36
Hence, the Consumer Price Index Number for the year 2010 (base year 2000) is approximately 138.36.
Que-4: The price of six different commodities for years 2009 and year 2011 are as follows:
| Commodities | A | B | C | D | E | F |
|---|---|---|---|---|---|---|
| Price in 2009 (₹) | 35 | 80 | 25 | 30 | 80 | x |
| Price in 2011 (₹) | 50 | y | 45 | 70 | 120 | 105 |
The index number for the year 2011 taking 2009 as the base year for the above data was calculated to be 125. Find the values of x and y if the total price in 2009 is ₹ 360.
Sol: Given:
ΣP₀ (total price in 2009) = 360
From table:
35 + 80 + 25 + 30 + 80 + x = 360
250 + x = 360
x = 360 − 250 = 110
Now use Index Number formula:
Index Number = (ΣP₁ / ΣP₀) × 100
Given Index Number = 125
So,
125 = (ΣP₁ / 360) × 100
ΣP₁ = (125 × 360) / 100 = 450
Now find ΣP₁ using table:
50 + y + 45 + 70 + 120 + 105 = 450
(390 + y) = 450
y = 450 − 390 = 60
Hence, the values are:
x = 110 and y = 60
–: End Index Numbers Class 11 OP Malhotra Exe-30C ISC Maths Ch-30 Solutions :–
Return to :- OP Malhotra ISC Class-11 S Chand Publication Maths Solutions
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