Question

A and b run a kilometre and a wins by 20 second. A and c run a kilometre and a wins by 250 m. When b and c run the same distance, b wins by 25 second. The time taken by a to run a kilometre is

Answer 1

A and B run a kilometers and a wins by 20second and 25second

A and c run a kilometers and a wins by 250m

the Time taken by a to run a kilometers is

20/25×250/c

20×10

200 kilometer

Answer 2

a  time requirement   to run 1 kilometre is 135 sec.

Step-by-step explanation:

Given:

1 kilometre distance run by a & b  and a wins by 20 Seconds.

b & c run the same distance b wins by 25 seconds.

1 kilometre distance run by a & c and a wins by 250 m.

 To Find:

a time requirement  a to run 1 kilo meter.

Formula Used:

Speed= Distance/ Time

Solution:

Let a run 1 km distance in P sec.

As given - 1 kilometre distance run by a & b  and a wins by 20 sec.

a runs 1 km distance in P sec. then b runs 1 km distance in ( P+20) sec.

As given - b & c run the same distance b wins by 25 sec.

b runs 1 km distance in (P+20 )sec. then c runs 1 km distance in ( P+45) sec.  

As given - 1 milometer distance run by a & c and a wins by 250 m.

a run 1 km distance  then c run 750 distance in the same time.

Also c covers  750 meters in time P which is same  as taken by a to run  1 km distance.

c  runs  750 meters in time P.

Then time required by c to run 1000 meter (1 km) $=\frac{P}{750} \times 1000$

From above c  runs 1 km distance in ( P+45) sec.

Then         $\frac{P}{750} \times 1000 = P+45$

                 $1000P=750P+750 \times 45$

                 $250P=750 \times 45$

                 $P= 135 sec.$

a  time requirement   to run 1 kilo meter is 135 sec.

Thus, a  time requirement  a to run 1 kilo meter is 135 sec.