Question

A train starts traveling from NY to LA at 7am at the speed of 60 mph three hours late another train starts following the first train at the speed of 80 mph how many hours will it take the second train to catch the first train?

Answer 1

Step-by-step explanation:

s1=v1*t1

s2=v2*t2

and s1=s2 because they catch up.

so v1*t1=v2*t2

60*t1=80*t2

and t2=t1-3 as it started 3 hours later.

so

60t1=80(t1-3)=80t1-240

so 20t=240

and t=12 hours ANSWER.

VERIFY:

12*80-12*60 is equal to

240 km from starting point

diff of speeds is 20 kmph