Answer:
Solution given:
since Rosie walked 18 km INA first day.
so
first term[a]=18km
again
she walked 90% of what she walked the day before which means
common ratio decreasing
common ratio[r]90%=0.9
sum of 10th day
=?
no of term (n)=10
now
we have
substituting value:
=
=117.28km
in nearest 10 it is 117km
the total distance Rosie had travelled by the end of 10 days is 117km.