APTITUDE FORMULAS
From Important Topics
SPEED, TIME AND DISTANCE
1. km/hr to m/s conversion:
a km/hr 5
ax m/s.
= 18
2. m/s to km/hr conversion:
1
a m/s = a x 8 km/hr.
5
3. Time taken by a train of length l metres to pass a pole or standing man or a signal post is
equal to the time taken by the train to cover l metres.
4. Time taken by a train of length l metres to pass a stationery object of length b metres is the
time taken by the train to cover (l + b) metres.
5. Suppose two trains or two objects bodies are moving in the same direction at u m/s and v m/s,
where u > v, then their relative speed is = (u - v) m/s.
6. Suppose two trains or two objects bodies are moving in opposite directions at u m/s
and v m/s, then their relative speed is = (u + v) m/s.
7. If two trains of length a metres and b metres are moving in opposite directions at u m/s
and v m/s, then:
(a + b)
The time taken by the trains to cross each other = sec.
(u + v)
8. If two trains of length a metres and b metres are moving in the same direction at u m/s
and v m/s, then:
(a + b)
The time taken by the faster train to cross the slower train = sec.
(u - v)
9. If two trains (or bodies) start at the same time from points A and B towards each other and
after crossing they take a and b sec in reaching B and A respectively, then:
(A's speed) : (B's speed) = (b : a)
10. In case of platform and train : speed of train =(length of platform + length of train)/ time.
11. If man is standing on platform then speed of train=length of train/time.
From Important Topics
SPEED, TIME AND DISTANCE
1. km/hr to m/s conversion:
a km/hr 5
ax m/s.
= 18
2. m/s to km/hr conversion:
1
a m/s = a x 8 km/hr.
5
3. Time taken by a train of length l metres to pass a pole or standing man or a signal post is
equal to the time taken by the train to cover l metres.
4. Time taken by a train of length l metres to pass a stationery object of length b metres is the
time taken by the train to cover (l + b) metres.
5. Suppose two trains or two objects bodies are moving in the same direction at u m/s and v m/s,
where u > v, then their relative speed is = (u - v) m/s.
6. Suppose two trains or two objects bodies are moving in opposite directions at u m/s
and v m/s, then their relative speed is = (u + v) m/s.
7. If two trains of length a metres and b metres are moving in opposite directions at u m/s
and v m/s, then:
(a + b)
The time taken by the trains to cross each other = sec.
(u + v)
8. If two trains of length a metres and b metres are moving in the same direction at u m/s
and v m/s, then:
(a + b)
The time taken by the faster train to cross the slower train = sec.
(u - v)
9. If two trains (or bodies) start at the same time from points A and B towards each other and
after crossing they take a and b sec in reaching B and A respectively, then:
(A's speed) : (B's speed) = (b : a)
10. In case of platform and train : speed of train =(length of platform + length of train)/ time.
11. If man is standing on platform then speed of train=length of train/time.
