Dr. Miriam Johnson has been teaching accounting for over 20 years. From her experience, she knows that 60% of her students do ho
1 answer:
You might be interested in
Answer:
B. 1.4 feet
Step-by-step explanation:
Let, the amount of increase be 'x' ft.
Since, the length and width of the canvas are 4 ft and 3 ft respectively.
Thus, area of the canvas, = length × breadth = 4 × 3 = 12 ft²
Since, the area of display model is twice the area of the canvas. We have,
= 2 ×
i.e. = 2 × 12
i.e. = 24 ft².
As, the length and width of the canvas are increased by 'x'.
The, length and width of the display model are (x+4) ft and (x+3) ft.
So, we get,
= length × breadth = (x+4) × (x+3) =
Since, = 24 ft²
i.e. = 24
i.e.
Solving the quadratic equation, we get,
i.e. x = -8.4 and x= 1.4
Since, the value of x cannot be negative.
Thus, x = 1.4 feet.
Solution:
Formula for radioactive Decay is given by
= Initial Population
R = Remaining population after time in hours
Rate of Decay = S % per hour
Initial Population = 72 grams
Final population = 15 grams
Rate of Decay = 35 % per hour
Substituting the values to get value of t in hours
→→1 St expression
But taking positive value of t , that is after 3.64 hours the sample of 72 grams decays to 15 grams at the rate of 35 % per hour.
Now , it is also given that, Once the sample reaches a mass of 15 grams, Billy will continually add more of the compound to keep the sample size at a minimum of 15 grams.
Substituting these in Decay Formula
Final Sample = 15 gm
Starting Sample = 15 +k, where k is amount of sample added each time to keep the final sample to 15 grams.
Time is over 3.64 hours i.e new time = 3.64 + t
Rate will remain same i.e 35 % per hour.
→→→ Final expression (Second) , that is inequalities can be used to determine the possible mass of the radioactive sample over time.