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For 4 le r le n, ((n),(r))+4((n),(r+1)...

For `4 le r le n`,
`((n),(r))+4((n),(r+1))+6((n),(r+2))+4((n),(r+3))+((n),(r+4))` equals

A

`""^(n+4)C_(r)`

B

`""2.^(n+4)C_(r-1)`

C

`""4.^(n)C_(r)`

D

`""11.^(n)C_(r)`

Text Solution

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The correct Answer is:
A
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OBJECTIVE RD SHARMA ENGLISH-PERMUTATIONS AND COMBINATIONS-Chapter Test
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  2. In a circket charmpionship there are 36 matches. The number of teams i...

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  3. For 4 le r le n, ((n),(r))+4((n),(r+1))+6((n),(r+2))+4((n),(r+3))+((...

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  4. The total number of numbers greater than 100 and divisible by 5, that ...

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  5. Find the number of words that can be made out of the letters of the ...

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  6. Number of numbers greater than 24000 can be formed by using digits 1,2...

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  7. Write the number of words that can be formed out of the letters of the...

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  8. How many different committees of 5 can be formed from 6 men and 4 wome...

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  9. The number of ways to rearrange the letters of the word CHEESE is

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  10. If \ ^(k+5)P(k+1)=(11(k-1))/2dot\ ^(k+3)P(k\ )Pk then the values of k ...

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  11. Find the number of proper factors of the number 38808. also, find sum ...

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  12. In a party 15 people shake their hands with each other. How many tim...

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  13. The number of ways in which 5 beads of different colours can be made i...

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  14. Find number of ways that 8 beads o different colors be strung as a ...

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  15. There are n points in a plane of which 'p' points are collinear. How m...

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  16. The number of 4 digit even numbers that can be formed using 0, 1, 2, 3...

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  17. The number of ways in which 21 objects can be grouped into three group...

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  18. Let L1 and L2 be two lines intersecting at P If A1,B1,C1 are points o...

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  19. In a plane there two families of lines : y=x+r, y=-x+r, where r in {0,...

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  20. How many words can be formed out of the letters of the word, ARTICLE, ...

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