Here, the distance traveled is not given, but Irina's bike-riding speed is: it is 16 mph.
Let the distance traveled be d. Then d = (27 mph)(0.4 hr) = 10.8 miles.
By bicycle, distance = rate times time. Here, 10.8 miles = (16 mph)(time), and so
10.8 mi
time = --------------- = 0.675 hour (40.5 minutes).
16 mph
X=4 is the answer to this question
Y=2x + 6. ( because 2x is 2 quarters a day and you started with 6
A)
X/3 -2 = 6
Add 2 to both sides:
X/3 = 8
Multiply both sides by 3:
X = 24
B)
X/5 +1 = 5
Subtract 1 from both sides:
X/5 = 4
Multiply both sides by 5:
X = 20
The half life of the radioactive isotope to the nearest tenth is 0.83 days.
<h3>What is rate of radioactive decay?</h3>
The rate of radioactive decay is the rate at which a radioactive isotope is disintegrated. The half life is the time taken for half of the original amount of radioactive isotope to remain.
Given that;
t/12 = 0.693/k
Where;
t1/2 - half life
k =decay constant
t/12 = 0.693/0.84
t/12 = 0.83 days
Learn more about half life:brainly.com/question/24710827
#SPJ4
