The length Q of a rectangle is decreased by 15% and its width is increased by 40%. Does the area of the rectangle decrease or increase and by what percent?
Options:
(A) Decreases by 19%
(B) Decreases by 25%
(C) Increases by 6%
(D) Increases by 19%
(E) Increases by 25%
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Let the length Q of the rectangle be 100x, and width be 100y. Area = 100x * 100y = 10000xy
Now after the change Length = 85x, and width = 140 y. Area = 11900xy
% Change = (11900xy - 10000xy)/(10000xy) = 19 % Increase. Hence So the answer is: (D).
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If 85 percent of the test takers taking an old paper and pencil GMAT exam answered the first question on a given math section correctly, and 70 percent of the test takers answered the second question correctly, and 5 percent of the test takers answered neither question correctly, what percent answered both correctly?
Options:
(A) 60 %
(B) 65 %
(C) 70%
(D) 75%
(E) 80%
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{Total} = {First correctly} + {Second correctly} - {Both correctly} + {Neither correctly}
100 = 85 + 70 - {Both correctly} + 5
{Both correctly} = 60. So the answer is: (A).
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A man rows his boat 80 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
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Speed downstream = d/t = 80/(2 1/2) = 32 kmph
Speed upstream = d/t = 45/(2 1/2) = 18 kmph
The speed of the stream = (32 - 18)/2 = 7 kmph So the answer is: (E).
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