two persons A and B start walking in opposite directions from a point .A travel twice as fast as B .the speed at which B Travels is 1 kilometre per hour .if A travels 2 km and turns back and starts working towards B at what distance from the starting point will a cross b.??
Answers
Answer:
Step-by-step explanation:
Speed of B = 1 km/hr
⇒Speed of A = 2 x speed of B = 2 x 1 Km/hr = 2 Km/hr
Time taken by A to travel 2 Km = distance/speed = 2/2 = 1 hour
Distance traveled by B in one hour = Speed x time = 1 Km/hr x 1 hr = 1 Km
Hence, when A has traveled 2 Km and take a turn, B was at 1 Km away from that point. At the point where A will cross B, both of them will be covering that much distance in same period of time.
Let B covers 'x' Km when he is crossed by A
Time taken by B = x/1 = x --------------------------- (1)
A will cover (1 + x) km to cross B
Time taken by A = (1 + x)/2 ---------------------------- (2)
Equating (1) and (2)
x = (1+x)/2
2x = 1 + x
x = 1 Km
Hence distance from starting point = (1 +1) Km = 2 Km
Answer:
At 4 km from starting point a will cross b
Step-by-step explanation:
Speed of B = 1km/Hr
Speed of A = 2 * 1 = 2 km/Hr
Distance of 2 km is covered by A in = 2/2 = 1 hr
Distance covered by B in 1 hr = 1 * 1 = 1 km
Distance between A & B = 2 + 1 = 3 km
Now A has to cover 3 km more than B to cross B
Let say after t hrs A cross B
Distance covered by A in t hrs = 2t km
Distnace covered by B in t hrs = t km
2t = t + 3
=> t = 3
after 3 hrs A will cross B
Distance covered in 3 hrs = 2 * 3 = 6 km
2km is to return at original point
so distance from Starting point = 6 -2 = 4 km
At 4 km from starting point a will cross b