There are 10person among whom 2are brother. The total no.of ways in which these persons can be seated around a round table so that exactly 1person sit between the brothers, is equal to?
Options:
(A) 4!*2!
(B) 7!*2!
(C) 6!*1!
(D) 2!*1!
(E) 5!*1!
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Total number of ways = 7!*2!. So the answer is: (B).
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10 books are placed at random in a shelf. The probability that a pair of books will always be together is?
Options:
(A) 1/6
(B) 1/7
(C) 1/5
(D) 1/9
(E) 1/2
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10 books can be rearranged in 10! ways consider the two books taken as a pair then number of favourable ways of getting these two books together is 9! 2!
Required probability = 1/5 So the answer is: (C).
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If the personal income tax rate is lowered from 42% to 32%, what is the differential savings for a tax payer having an annual income before tax to the tune of $42400?
Options:
(A) $3500
(B) $5000
(C) $4240
(D) $7000
(E) $10000
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Saving = (42-32)% of 42400 = 4240. So the answer is: (C).
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