Question

if the 2nd, 4th, 6th and 8th letters of the word 'POLLUTION' are selected, how many meaningful word made using all the four selected letters?
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Answer 1

Answer:

a

4

−b

4

+2b

2

−1

Above terms can be written as ,

a

4

−(b

4

−2b

2

+1)

We know that (a−b)

2

=a

2

−2ab+b

2

a

4

−((b

2

)

2

)−(2×b

2

×1)+1

2

)

(a

2

)

2

−(b

2

−1)

2

We know that a

2

−b

2

=(a+b)(a−b)

(a

2

+b

2

−1)(a

2

−b

2

+1)

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Answer 2

Answer:

tool

only one meaningful