Question: A man rows his boat 90 km downstream and 72 km upstream, taking 3 hours each time. Find the speed of the stream?
Options:
(A) 6
(B) 5
(C) 7
(D) 3
(E) 2
Ans: (D)
CoT: Speed downstream = d/t = 90/3 = 30 kmph
Speed upstream = d/t = 72/(3) = 24 kmph
The speed of the stream = (30 - 24)/2 = 3 kmph
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Question: 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
Ans: (C)
CoT: Saving = (42-32)% of 42400 = 4240.
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Question: Rs.800 amounts to Rs.920 in 3 years at simple interest. If the interest is increased by 3%, it would amount to how much?
Options:
(A) 226
(B) Rs.992
(C) 665
(D) 771
(E) 211
Ans: (B)
CoT: (800*3*3)/ 100 = 72
920 + 72 = 992
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