In a kilometre race, A beats B by 30 seconds and B beats C by is seconds. If A beats C by 180 metres, the time taken by A to run 1 kilometre is 1). 250 sec. 2). 205 sec. 3). 200 sec. 4). 210 sec.
A beats B by 30 seconds and
B beats C by 15 seconds.
Clearly, A beats C by 45 seconds.
Also, A beats C by 180 metres.
Hence, C covers 180 metres in
45 seconds.
Speed of C =$\frac{180}{45}$ = 4 m/sec
Time taken by C to cover 1000 m
=$\frac{1000}{4}$ = 250 sec.
so that,
Time taken by A to cover 1000 m
= 250–45 = 205 sec.