Answer:
4 hours
Step-by-step explanation:
The amount remaining at the end of each hour is 0.85 of the amount at the start of the hour. You want to find the exponent such that ...
... 0.85^x = 0.5 . . . . . x = the number of hours until half is left
... x·log(0.85) = log(0.5) . . . . . take the log to turn it to a linear equation
... x = log(0.5)/log(0.85) ≈ 4.265024
Rounded to the nearest hour, x = 4.
For this case we must find the value of the variable "x" of the following equation:

We multiply by 3 on both sides of the equation:

We divide between 2 on both sides of the equation:

We subtract 7 on both sides of the equation:

Answer:
Option B
Answer: 27cm²
Step-by-step explanation:
lets take the width as x and length as 3x( since length is 3 times the width)…
Perimeter of the rectangle is 24 cm( 2*(l+b))= 2×(3x+x):24
2×4x=24
8x=24
X( width): 24/8=3cm
Length= 3x: 3*3=9cm
Area of the rectangle: ( l*w)= 9×3: 27cm²
Answer:
60 pounds
Step-by-step explanation:
Let the normal price be p. The "25%-off" sale price is then 0.75p, and this 0.75p equals 45 pounds. Dividing both sides by 0.75 results in p = 60 pounds.