Answer:
18 minutes
Step-by-step explanation:
A = A₀ (½)^(t / T)
where A is the final amount,
A₀ is the initial amount,
t is the time,
and T is the half life.
A = 140 when t = 10. Solve for the half life:
140 = 700 (½)^(10 / T)
0.2 = ½^(10 / T)
log 0.2 = (10 / T) log 0.5
10 / T = 2.32
T = 4.31
When A = 40, t is:
40 = 700 (½)^(t / 4.31)
0.057 = ½^(t / 4.31)
log 0.057 = (t / 4.31) log 0.5
t / 4.31 = 4.13
t = 17.8
Rounded to the nearest whole number, it takes 18 minutes.
Answer:
Step-by-step explanation:
Its is a linear equation .that is to day a simple equation of a line whose values can be obtained through their intercept.intercept on x axis, y is zero and vice versa
Answer:
7 presents
Step-by-step explanation:
He can wrap the 7 very small presents with that amount of tape
Answer: 
Step-by-step explanation:
1. Substitute 
into first equation and solve for "x" in order to find the x-intercept of the first line:
2. Substitute 
into the first equation and solve for "y" in order to find the y-intercept of the first line:
Knowing that first line passes through the points 
and 
, you can graph it.
3. Substitute into second equation and solve for "x" in order to find the x-intercept:
4. Substitute into the second equation and solve for "y" in order to find the y-intercept of the second line:
Knowing that second line passes through the points 
and 
, you can graph it.
The solution of the system of equations is the point of intersection between the lines. Therefore, the solution of this system is:
In this question weight of a flea and an ant is given, but their units are different. So comparing and finding out the weight of flea and ant would be difficult. First thing that needs to be done is to bring the units of both the flea and the ant under same unit.
Weight of flea = 8 decigrams
Weight of ant = 3 milligrams.
Now let us convert the weight of the flea from decigrams to milligrams.
We already know that
1 decigram = 100 milligram
Then
8 decigrams = 100 * 8 milligrams
= 800 milligrams
Then
The weight by which the flea is greater than the ant = (800 - 3) milligrams
= 797 milligrams.
So the flea weighs 797 milligrams more than the ant.
