motion physics question. please help?

Question

a tortoise can run with a speed of 16.0cm/s, and hare can run exactly 15 times as fast. In a race, they both start at the same time, but the hare stops to rest for 120 seconds. The tortoise wins by 20.0cm. How long does the race takes? What is the length of the race.

Answer 1

distance of the tortoise is
dT=16*t

the distance of the hare is
dH=dT-20
=16*15*(t-120)
rearranging
dT=16*15*(t-120)+20
solve for t
16*t=16*15*(t-120)+20

16*14*t=16*15*120-20
t=128.5 seconds

dT=2056 cm

check with dH,
same answer

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