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