Rationale: D = 100 + 150 = 250
S = 36 * 5/18 = 10 mps
T = 250/10 = 25 se
The answer: (C)
Question: How many seconds will a train 100 meters long take to cross a bridge 150 meters long if the speed of the train is 36 kmph?
Options:
(A) 65 sec
(B) 88 sec
(C) 25 sec
(D) 88 sec
(E) 55 sec
Reasoning: Present age of total members = 6 X 28 = 168
7 yrs back their ages were = 6 x 7 = 42
Ages at the birth of youngest member = 168 - 42 = 126
Therefore, avg age at the birth of youngest member = 126/6 = 21.
Ans: (C)
Question: The average age of a family of 6 members is 28 years.If the age of the youngest member is 7 years,what was the average age of the family at the birth of the youngest member?
Options:
(A) 15
(B) 18
(C) 21
(D) 12
(E) 19
Rationale: Distance traveled by Eddy = 450 km
Time taken by Eddy = 3 hours
Average speed of Eddy = 450/3 = 150 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 = 150/75 = 2
The answer: (B)
Question: 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 450 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) 2
(C) 8/5
(D) 5/8
(E) 5/3
Reasoning: 8/12 + 6/x = 1
X = 18 days
Ans: (A)
Question: A can do a piece of work in 12 days. When he had worked for 2 days B joins him. If the complete work was finished in 8 days. In how many days B alone can finish the work?
Options:
(A) 18 days
(B) 11 days
(C) 77 days
(D) 188 days
(E) 66 days
Rationale: Distance covered in first two hours = 10 2 = 20 km
Distance covered in next two hours = 12 2 = 24 km
Distance covered in next two hours = 14 2 = 48 km
Distance covered in first six hours
20 + 24 + 48 = 92 km
Remaining distance = 8 km
92 + 8 = 100 km
The answer: (B)
Question: A woman begins bicycling with a pace of 10 kmph and she increases her pace every two hours by 2 kmph. She rests from bicycling 2 hours after her pace reaches her maximum speed of 14 kmph. She does a cool-down for the final 8 km at a pace of 2 kmph. How far in km did she bicycle?
Options:
(A) 96 km
(B) 100 km
(C) 106 km
(D) 116 km
(E) 126 km
Rationale: Other number = (11 * 7700)/275 = 308.
The answer: (C)
Question: The H.C.F of two numbers is 11 and their L.C.M is 7700. If one of the numbers is 275, then the other is:
Options:
(A) 279
(B) 283
(C) 308
(D) 318
(E) 328