The price of a cellular telephone is based on peak and nonpeak service. kelsey used 45 peak and 50 nonpeak minutesand was charged $27.75. that same moth ,mitch used 70 peak minutes and 30 nonpeak minutes for a total charge of $36. what are the rates per minute for peak and nonpeak time?

Question

anonymous · Answer

In 1990, the population of the Midwest was about 60 million. During the 1990’s, the 
population of this area increased an average of about 0.4 million per year.
The population in the West was about 53 million in 1990. The population of this area 
increased an average of about 1 million per year during the 1990s.

anonymous · Answer

Assume that the rate of growth of these areas remains the same . Estimate when the population of the West Would be equal to the Midwest.

anonymous · Answer

@hartnn @mathmath333

anonymous · Answer

Sorry that i tool so long to post the question :)

kamille · Answer

hm maybe
$$60(1+0.4)^{n}=53(1+1)^{n}$$ 

where you need to find n (years)

However,I dunno,maybe you had to convert 0.4 and 1 into %

kamille · Answer

it is because $$S=S _{0}(1+\frac{ p }{ 100 })^{n}$$

and both of them must be equal

kamille · Answer

@amistre64

anonymous · Answer

This is what I came up with 
60+.4t=p
53+t=p

campbell_st · Answer

well they look linear to me

let t = years  P = population (millions)


MidWest: P = 0.4t + 60 

West:      P = t + 60

hope it makes sense

campbell_st · Answer

so all you need to do now is equate them ans solve for t

0.4t + 60 = t + 53

hope it helps

anonymous · Answer

So the answer would be 11.7 by solving those equations right ?

campbell_st · Answer

oops west should be P = t + 53

campbell_st · Answer

that's correct

anonymous · Answer

Can you help me with another?

campbell_st · Answer

if you post a new question there are lots of people who can help.

anonymous · Answer

the price of a cellular telephone is based on peak and nonpeak service. kelsey used 45 peak and 50 nonpeak minutesand was charged $27.75. that same moth ,mitch used 70 peak minutes and 30 nonpeak minutes for a total charge of $36. what are the rates per minute for peak and nonpeak time?

campbell_st · Answer

well let p = peak and n = non peak 

 Kelsey:    45p + 50n = 27.75
Mitch:      70p + 30n = 36.00

you need to solve simultaneously     I'd probably use substitution 

take the 1st equation and   50n = 27.75 - 45p

then divide every term by  5      10n = 5.55 - 9p

now substitute into the 2nd equation 

70p + 3(5.55 - 9p) = 36.00

and solve for p. 

then when you get that you can solve for n

hope it helps

anonymous · Answer

Thank you all for your help :)