Answer:
18
Step-by-step explanation:
30*0.4=12
This means 40% of 30 is 12 and Ana has completed 12 problems.
30-12 = 18, so she still needs to do 18 problems.
This exponential growth/decay (in this case decay because r<1) of the form:
f=ir^t, f=final value, i=initial value, r=common ratio or "rate", t=time.
Since the population decreases by 4.5% each year the common ratio is:
r=(100-4.5)/100=0.955 so we can say
P(t)=8500(0.955^t)
....
7000=8500(0.955^t)
14/17=(955/1000)^t taking the natural log of both sides
ln(14/17)=t ln(955/1000)
t=ln(14/17)/ln(955/1000)
t≈4.22 years (to nearest hundredth of a year)
Since t is the years since 2010, the population will fall to 7000 in the year (2010+4.22=2014.22, more than four years will have elapsed) 2015.
Photomath is useful for these kinds of problems
Answer:
The initial cost of the cell phone was $364
Step-by-step explanation:
Since there was a 30% markup, 70% of the new cost is the initial cost. Multiply 520 by 0.7 on a calculator and you get 364
Answer: She will need 142 ft of curtain.
Step-by-step explanation:
Hi, first we have to convert the length of the curtain from inches to foot.
Since 1 inch = 1/12ft
For 24 inches:
24 inches x 1/12 = 2 ft
Since the company wants to make 71 curtains, we have to multiply the length of each curtain (2ft) by 71.
2ft x 71 = 142ft
She will need 142 ft of curtain.
Feel free to ask for more if needed or if you did not understand something.
