Question

Eudora ran from her home to her secret laboratory at an average speed of 12km/h , t. She then took one of her jetpacks and flew to her school at an average speed of 76 km/h . Eudora traveled a total distance of 120 kilometers, and the entire trip took 2 hours.

Answer 1

Step-by-step explanation:

She ran for RR hours at 12 km/h. She jetpacked for JJ hours at 76 km/h.

We are told that J+R=2J+R=2 (so J=2−RJ=2−R) and that 12R+76J=12012R+76J=120.

By substituting for JJ we get:

12R+76(2−R)=12012R+76(2−R)=120

⇒12R+152−76R=120⇒12R+152−76R=120

⇒−64R+152=120⇒−64R+152=120

⇒32=64R⇒32=64R

⇒R=12⇒R=12.

∴∴ She ran for half an hour and jetpacked for one and half hours.