The following table gives the total weightage of the top 20% and the total weightage of the bottom 20% of the companies that constitute the index, for twelve of the major stock market indices of the world. In each index, the companies that comprise the index are first arranged in the descending order according to their respective weightages in the index. The top p%, and the bottom p% of the companies would then be the first p% and the last p% of the companies in the list.
Sl. No. | Index | Weightage of bottom 20% of the companies | Weightage of top 20% of the companies |
---|---|---|---|
1 | SENSEX | 5.5% | 43% |
2 | NIKKEI | 7.2% | 41.6% |
3 | KOPSI | 3.8% | 39.8% |
4 | DOW JONES | 2.7% | 44.1% |
5 | NIFTY | 5.1% | 46.4% |
6 | NASDAQ | 3.5% | 39.4% |
7 | FTSE 100 | 2.8% | 43.4% |
8 | HANG SENG | 3.1% | 47.1% |
9 | DAX | 5.9% | 38.6% |
10 | STRAITS TIMES | 6.3% | 39.5% |
11 | KLSE | 7.2% | 37.6% |
12 | S & P 500 | 4.1% | 42.6% |
To determine for how many indices the weightage of the bottom 50% of the companies is less than 30%, we start by understanding that the top 20% and bottom 20% weightages are given. By elimination, the remaining middle 60% of companies will have a cumulative weightage of:
Weightage of middle 60% = 100% - Weightage of top 20% - Weightage of bottom 20%
Therefore, weightage of bottom 50% of companies = Weightage of middle 60% + Weightage of bottom 20%. We need this to be less than 30% for the bottom 50%.
Let's calculate for each index:
Index | Weightage of top 20% | Weightage of bottom 20% | Weightage of middle 60% | Bottom 50% |
---|---|---|---|---|
SENSEX | 43% | 5.5% | 51.5% | 5.5% + 25.75% = 31.25% |
NIKKEI | 41.6% | 7.2% | 51.2% | 7.2% + 25.6% = 32.8% |
KOPSI | 39.8% | 3.8% | 56.4% | 3.8% + 28.2% = 32% |
DOW JONES | 44.1% | 2.7% | 53.2% | 2.7% + 26.6% = 29.3% |
NIFTY | 46.4% | 5.1% | 48.5% | 5.1% + 24.25% = 29.35% |
NASDAQ | 39.4% | 3.5% | 57.1% | 3.5% + 28.55% = 32.05% |
FTSE 100 | 43.4% | 2.8% | 53.8% | 2.8% + 26.9% = 29.7% |
HANG SENG | 47.1% | 3.1% | 49.8% | 3.1% + 24.9% = 28% |
DAX | 38.6% | 5.9% | 55.5% | 5.9% + 27.75% = 33.65% |
STRAITS TIMES | 39.5% | 6.3% | 54.2% | 6.3% + 27.1% = 33.4% |
KLSE | 37.6% | 7.2% | 55.2% | 7.2% + 27.6% = 34.8% |
S & P 500 | 42.6% | 4.1% | 53.3% | 4.1% + 26.65% = 30.75% |
Hence, for the indices where weightage is <30% (highlighted in calculation): DOW JONES, NIFTY, FTSE 100, HANG SENG. Therefore, 4 indices satisfy the condition.
The objective is to determine the minimum weightage of a company among the top 10 companies in the SENSEX.
Given that the SENSEX consists of 30 companies, 20% of these companies would account for the top 6 companies (20% of 30 = 6). Therefore, the weightage of these top 6 companies comprises 43% of the SENSEX.
Since the question asks for the minimum weightage among the top 10 companies, we will include 4 additional companies to complete the top 10 companies. We need to distribute the remaining (top) weightage of these 4 companies.
Considering that the bottom 20% of the companies holds a 5.5% weightage, and these account for the bottom 6 companies, the remaining weightage for the middle tier companies is calculated as follows:
Total weightage of all companies is 100%. If the bottom 20% accounts for 5.5%, then the remaining weightage for the top 80% equals 94.5%.
Out of this 94.5%, the top 6 companies account for 43% as mentioned. This leaves 94.5% - 43% = 51.5% for the remaining 80% of companies not in the bottom or top tiers.
The 24 companies that are neither in the top 20% nor in the bottom 20% have a total weightage of 51.5%. This approximates to a 2.15% weightage for each of these middle-tier companies (51.5% divided by 24).
As a result, the minimum weightage for a company among the top 10 companies would be slightly above any of the individual middle-tier companies' average weightage.
The smallest choice that could be logically given to a company among the top 10 in consideration of the average and distribution would be 2.4%.
The correct answer is: 2.4%
To determine for how many indices the weightage of the top 40% of the companies is definitely more than 60%, we need to examine if the accumulated weightage of the top 20% plus another 20% will exceed 60%.
Given the weightage of the top 20% for each index from the table:
Index | Weightage of top 20% |
---|---|
SENSEX | 43% |
NIKKEI | 41.6% |
KOPSI | 39.8% |
DOW JONES | 44.1% |
NIFTY | 46.4% |
NASDAQ | 39.4% |
FTSE 100 | 43.4% |
HANG SENG | 47.1% |
DAX | 38.6% |
STRAITS TIMES | 39.5% |
KLSE | 37.6% |
S & P 500 | 42.6% |
To ensure the top 40% exceeds 60%, the weightage of the top 20% must be at least 40%, ensuring that adding another 20% brings it comfortably over 60%.
We identify these indices where weightage of top 20% ≥ 40%:
There are 7 indices where the top 20% weightage is above 40%.
A | B | C | D | Average |
---|---|---|---|---|
3 | 4 | 4 | ? | 4 |
3 | ? | 5 | ? | 4 |
? | 3 | 3 | ? | 4 |
? | ? | ? | ? | 4.25 |
4 | 4 | 4 | 4.25 |