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
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Q2. If the average age of A, B and C is 22 years and the average age of B and C is 25 years, then find the age of A after 9 years from now. Q2. If the average age of A, B and C is 22 years and the average age of B and C is 25 years, then find the age of A after 9 years from now.
(A) 25 years (A) 25 years
(B) 35 years (B) 35 years
(C) 50 years (C) 50 years
(D) 45 years (D) 45 years
Answer: (A) 25 years Answer: (A) 25 years
25 years
=> A+B+C = 22*3
=> A+(B+C) = 66
=> A+(25*2) = 66
=> A = 66-50
=> A = 16
After 9 years A = 16+9 = 25 years25 years
=> A+B+C = 22*3
=> A+(B+C) = 66
=> A+(25*2) = 66
=> A = 66-50
=> A = 16
After 9 years A = 16+9 = 25 years
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Q3. What is the term for the distance around a shape? Q3. 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.
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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.
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Q5. When the numerator of a fraction is multiplied by 4 and the denominator by 9, the fraction reverses. The fraction is Q5. When the numerator of a fraction is multiplied by 4 and the denominator by 9, the fraction reverses. The fraction is
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Q6. When the numerator of a fraction increases by 3, the fraction increases by its three-fourth. The numerator of the fraction is Q6. When the numerator of a fraction increases by 3, the fraction increases by its three-fourth. The numerator of the fraction is
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Q7. In a range of consecutive numbers starting with 1, all the even numbers are removed. From the remaining, consider the first 7 numbers. The sum of these 7 numbers is Q7. In a range of consecutive numbers starting with 1, all the even numbers are removed. From the remaining, consider the first 7 numbers. The sum of these 7 numbers is
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Q10. Three numbers are in the ratio 3:4:6 and their product is 1944. The largest of the numbers is. Q10. Three numbers are in the ratio 3:4:6 and their product is 1944. The largest of the numbers is.