Question

0.5
Walking at a speed of 15 kmph, Pamela reaches her office 9 minutes late. If she walks at 21 kmph, then she reaches 6 minutes early. How far is her office?
Ops: A.
KOD 14.875 km
225 km
13.125 km
D.
5.129 km​

Answer 1

Explanation:

Let T be the on-time time in minutes. Then the two formulas for distance D in km are:

D = (6/60)*(T+9) for a 5 km/hr pace

D = (9/60)*(T-6) for a 10 km/hr pace (I assume that is what was meant)

15(t+ 3/20 )=21(t - 1/10)

15t + 45/20 = 21t - 21/10

t= 9/4 + 21/10

t= 4.35