[Ques]: 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%
*Ans*: (D)
--CoT--: 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

[Ques]: A train of 25 carriages, each of 60 meters length, when an engine also of 60 meters length is running at a speed of 60 kmph. In what time will the train cross a bridge 2.5 km long?
Options:
(A) 4
(B) 3
(C) 5
(D) 7
(E) 9
*Ans*: (A)
--CoT--: D = 25 * 60 + 2500 = 4000 m
T = 4000/60 * 18/5 = 240 sec = 4 mins

[Ques]: By how much is 70% of 120 greater than 35% of 200.
Options:
(A) 15
(B) 14
(C) 13
(D) 16
(E) 17
*Ans*: (B)
--CoT--: (70/100) * 120 â€“ (35/100) * 200
84 - 70 = 14

[Ques]: Eddy and Freddy start simultaneously from city A and they travel to City B and City C respectively. Eddy takes 3 hours and Freddy takes 4 hours to complete the journey. If the distance between City A and City B is 510 kms and City A and City C is 300 kms. What is the ratio of their average speed of travel? (Eddy: Freddy)
Options:
(A) 8/3
(B) 3/8
(C) 8/5
(D) 5/8
(E) 34/15
*Ans*: (E)

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
--CoT--: Distance traveled by Eddy = 510 km
Time taken by Eddy = 3 hours
Average speed of Eddy = 510/3 = 170 km/hour
Distance traveled by Freddy = 300 km
Time taken by Freddy = 4 hours
Average speed of Freddy = 300/4 = 75 km/hour
Ratio of average speed of Eddy to Freddy = 170/75 = 34/15