q: A man rows his boat 75 km downstream and 45 km upstream, taking 2 1/2 hours each time. Find the speed of the stream?
Options:
(A) 1 kmph
(B) 6 kmph
(C) 5 kmph
(D) 8 kmph
(E) 7 kmph
a: Speed downstream = d/t = 75/(2 1/2) = 30 kmph
Speed upstream = d/t = 45/(2 1/2) = 18 kmph
The speed of the stream = (30 - 18)/2 = 6 kmph The answer is (B).
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q: The speed of a boat in still water is 80kmph and the speed of the current is 20kmph. Find the speed downstream and upstream?
Options:
(A) 22 kmph
(B) 40 kmph
(C) 60 kmph
(D) 15 kmph
(E) 23 kmph
a: Speed downstream = 80 + 20 = 100 kmph
Speed upstream = 80 - 20 = 60 kmph The answer is (C).
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q: Solve below question 4x + 1 = 37
Options:
(A) -8
(B) -9
(C) -5
(D) 9
(E) 1
a: 1. Subtract 1 from both sides: 4x + 1 - 1 = 37 - 1 2. Simplify both sides: 4x = 36 3. Divide both sides by 4: 4. Simplify both sides: x = 9 The answer is (D).
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q: When tossed, a certain coin has equal probability of landing on either side. If the coin is tossed 3 times, what is the probability that it will land once on heads and twice tails?
Options:
(A) 1/3
(B) 1/6
(C) 1/4
(D) 1/8
(E) 1/5
a:
Must be once on heads and twice on tails
1/2*1/2*1/2 = 1/8 The answer is (D).
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