q: Three years ago, the average age of a family of 5 members was 17. A baby having been born, the average age of the family is the same today. What is the age of the child?
Options:
(A) 3
(B) 2
(C) 4
(D) 1
(E) 5
a: Present age of 5 members = 5 x 17 + 3 x 5 = 100 years
Also, present ages of 5 members + Age of the baby = 6 x 17 = 102 years
Age of the baby = 102 100 = 2 years. The answer is (B).
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q: If the average (arithmetic mean) of the four numbers K, 3K + 3, 3K 4 and 5K + 1 is 60, what is the value of K?
Options:
(A) 11
(B) 15 3/4
(C) 20
(D) 23
(E) 25 3/10
a: K + 3K +3 + 3K - 4 + 5K +1 = 12K
(12K)/4 = 60
12K = 60 * 4 = 240
K = 240/ 12 = 20. The answer is (C).
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q: If the personal income tax rate is lowered from 45% to 30%, what is the differential savings for a tax payer having an annual income before tax to the tune of $48000?
Options:
(A) $3500
(B) $5000
(C) $3150
(D) $7200
(E) $10000
a: Saving = (45-30)% of 48000 = 7200. The answer is (D).
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q: A number lock on a suitcase has 3 wheels each labelled with 10 digits from 0 to 9. If opening of the lock is a particular sequence of three digits with no repeats, how many such sequences will be possible?
Options:
(A) 720
(B) 760
(C) 680
(D) 780
(E) 880
a:
On first wheel there can be 10 digits. On the second wheel there will be one of the 9 digits and on the third wheel there will be 8 digits. Therefore, the number of numbers is
10 x 9 x 8 = 720 The answer is (A).
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