Two trains of 200 m and 100 m long are running parallel at the rate of 20 m/sec. and 22 m/sec. respectively. How much time will they take to cross each other, if the trains are running along the same direction? [#1132]
Q1. Two trains of 200 m and 100 m long are running parallel at the rate of 20 m/sec. and 22 m/sec. respectively. How much time will they take to cross each other, if the trains are running along the same direction? Q1. Two trains of 200 m and 100 m long are running parallel at the rate of 20 m/sec. and 22 m/sec. respectively. How much time will they take to cross each other, if the trains are running along the same direction?
(A) 120 sec (A) 120 sec
(B) 100 sec (B) 100 sec
(C) 60 sec (C) 60 sec
(D) 50 sec (D) 50 sec
Answer: (D) 50 sec Answer: (D) 50 sec
The difference of speed = 22m/s - 20m/s = 2m/s
As the train with speed 22m/s will cross the other, hence this train have to go the smallest length of the trains distance ahead of the other to cross completely.
Hence This train will be ahead of 100m with a speed of 2m/s.
Hence The time to cross each other will take = 100m / (2m/s)
= 50 secThe difference of speed = 22m/s - 20m/s = 2m/s
As the train with speed 22m/s will cross the other, hence this train have to go the smallest length of the trains distance ahead of the other to cross completely.
Hence This train will be ahead of 100m with a speed of 2m/s.
Hence The time to cross each other will take = 100m / (2m/s)
= 50 sec
Q1. A number is as much greater than 22 as is less than 72. Then the number is Q1. A number is as much greater than 22 as is less than 72. Then the number is
Q4. p, q, r are three numbers such that the LCM of p and q is q and the LCM of q and r is r. The LCM of p, q and r will be Q4. p, q, r are three numbers such that the LCM of p and q is q and the LCM of q and r is r. The LCM of p, q and r will be
(A) q (A) q
(B) r (B) r
(C) qr (C) qr
(D) pqr (D) pqr
Answer: (B) r Answer: (B) r
LCM will be r.
px= q and qy = r, hence r = pxy.LCM will be r.
px= q and qy = r, hence r = pxy.
Q5. At what speed should a car travel on a highway to reach a destination 12 km away in 15 minutes? Q5. At what speed should a car travel on a highway to reach a destination 12 km away in 15 minutes?
(A) 64 kmph (A) 64 kmph
(B) 84 kmph (B) 84 kmph
(C) 48 kmph (C) 48 kmph
(D) 36 kmph (D) 36 kmph
Answer: (C) 48 kmph Answer: (C) 48 kmph
12
---- x 60 = 48 KMPH
1512
---- x 60 = 48 KMPH
15
Q6. A man is 3 years older than his wife and four times as old as his son. If the son becomes 15 years old after 3 years, the present age of his wife is : Q6. A man is 3 years older than his wife and four times as old as his son. If the son becomes 15 years old after 3 years, the present age of his wife is :
(A) 60 years (A) 60 years
(B) 51 years (B) 51 years
(C) 48 years (C) 48 years
(D) 45 years (D) 45 years
Answer: (D) 45 years Answer: (D) 45 years
The son becomes 15 years old after 3 years.
Hence son's present age = 15 years - 3 years = 12 years
Man is four times as old as his son.
Hence Man's present age = 12 years * 4 = 48 years
Man is 3 years older than his wife.
Hence present age of his wife = 48 years - 3 years = 45 years.The son becomes 15 years old after 3 years.
Hence son's present age = 15 years - 3 years = 12 years
Man is four times as old as his son.
Hence Man's present age = 12 years * 4 = 48 years
Man is 3 years older than his wife.
Hence present age of his wife = 48 years - 3 years = 45 years.
Q7. A number was increased by 40% and thereafter decreased by 40%. The net change in the number in percentage is Q7. A number was increased by 40% and thereafter decreased by 40%. The net change in the number in percentage is
Q8. What is the term for the distance around a shape? Q8. What is the term for the distance around a shape?
(A) Area (A) Area
(B) Perimeter (B) Perimeter
(C) Volume (C) Volume
(D) Surface area (D) Surface area
Answer: (B) Perimeter Answer: (B) Perimeter
The perimeter is the distance around a shape, like the distance around a rectangle, triangle, or circle.The perimeter is the distance around a shape, like the distance around a rectangle, triangle, or circle.
Q9. The count of prime numbers between 80 and 100 is Q9. The count of prime numbers between 80 and 100 is
(A) 2 (A) 2
(B) 5 (B) 5
(C) 3 (C) 3
(D) 4 (D) 4
Answer: (C) 3 Answer: (C) 3
Prime numbers are numbers that are only divisible by 1 and themselves. Between 80 and 100, the prime numbers are 83, 89, and 97. Therefore, there are 3 prime numbers in this range.Prime numbers are numbers that are only divisible by 1 and themselves. Between 80 and 100, the prime numbers are 83, 89, and 97. Therefore, there are 3 prime numbers in this range.