Answer:
Eudora spent 0.5 hours from home to library and 1.5 hours from library to school
Step-by-step explanation:
Given
Home to Library:
-- Average Speed
Library to School
-- Average Speed
Total


Required
Determine the time taken from home to library and from library to school
Let the time spent from home to library be x. So, from library to school will be: 2 - x
So, we have:
Home to Library:
-- Average Speed
-- Time
Library to School
-- Average Speed
-- Time
Distance is calculated as:

Home to Library:



Library to School:



The total distance is 120km. So, we have:


Collect Like Terms



Solve for x


Recall that:


So, we have:


Answer: 21 square units
Step-by-step explanation:
We know that the area of parallelogram is given by:-

Let US denote the height of the Parallelogram RSTU with corresponding base ST.
By counting the distance between the points using grids or by distance formula,
US=
ST=
Now, the area of parallelogram RSTU is given by:-

Answer:
Step-by-step explanation:
Given a sample M(t)
M(t) = 120 • ( 81 / 625)^t
When is the fraction of the mass decay to 3/5 of it's mass
Generally
M(t) = Mo•(k^t)
The original mass is 120
Mo = 120
So, we want to find time when it decay to 3/5 of it's original mas
M = 3/5 × 120
M = 72
Then,
M(t) = 120 • ( 81 / 625)^t
72 = 120 • ( 81 / 625)^t
72 / 120 = ( 81 / 625)^t
0.6 = ( 81 / 625)^t
Take natural logarithmic of both sides
In(0.6) = In(81/625)^t
In(0.6) = t•In(81/625)
t = In(0.6) / In(81/625)
t = In(0.6) / In(0.1296)
t = 0.25 monthly
t = ¼ monthly