Question

Eudora ran from her home to her secret laboratory at an average speed of 12 km/h 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. How long did Eudora spend running, and how long did she spend flying using her jetpack?

Answer 1

Answer:

She spent 0.5 hrs running to her secret laboratory and 1.5 hrs flying using her jetpacks.

Step-by-step explanation:

Eudora ran from her home to her secret laboratory at an average speed of 12 km/h. The journey with her jet pack to her school has an average speed of 76km/hr. Eudora traveled a distance of 120 kilometers.  This means the total journey when she ran and flew she could cover a distance of 120 km and the entire trip took 2 hours.

The trip can be categories into two

when she ran to her secret laboratory

Speed = 12 km/hr

let the time she ran to her  secret laboratory  = a

speed = distance /time

distance = speed × time

distance = 12 × a

distance = 12a

when she flew to her school

speed = 76 km/hr

The time she flew to her school = 2 - a

speed = distance /time

distance = speed × time

distance = 76 × 2 - a

distance = 152 - 76a

Total distance of her entire trip = 120 km

total time = 2 hrs

Total distance can be represented as

12a +  152 - 76a = 120

-64a = 120 - 152

-64a = -32

divide both side by -64

a = -32/-64

a = 0.5 hrs

she spent 0.5 hrs running to her secret laboratory

Time she flew with her jetpacks = 2 - a = 2 - 0.5 = 1.5 hrs  

Answer 2

She ran 0.5 hours and flew 1.5 hours