A community for students.
Here's the question you clicked on:
 0 viewing
anonymous
 5 years ago
You have £1,000 in your savings account. At the end of each month, the bank adds an extra 0.2% of interest to the outstanding balance and you make a withdrawal of £10.
How much is in the savings account after this has happened for 36 months, rounded to the nearest pound?
(I guess you need to solve it with a linear difference equation, but I cannot figure it out)
anonymous
 5 years ago
You have £1,000 in your savings account. At the end of each month, the bank adds an extra 0.2% of interest to the outstanding balance and you make a withdrawal of £10. How much is in the savings account after this has happened for 36 months, rounded to the nearest pound? (I guess you need to solve it with a linear difference equation, but I cannot figure it out)

This Question is Closed

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0\[a ^{n}x _{0} +b (a ^{n}1)/(a1)\] I found this formula for it and it gives the good answer but I do not see why. (a^n=1.002^36 , xo=1000 , b=10)

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0yeah i have to write this down. certainly cannot do it on the fly. if at all!

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0wait, why isn't it just \[1000(1.002)^{10}10(1.002)^9\]?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0actually my exponents are ridiculous. it is 36 months not ten. so i think maybe \[1000(1.002)^{36}10(1.002)^{35}\]

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0i just wrote out the first three months and saw what i got.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0I am not sure here at all, I found that formula and it did give me the correct answer, but I can only see the answer unfortunately

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0first month P(1.002) second month (P(1.002)10)(1.002)=P(1.002)^210(1.002) third month (P(1.002)^210(1.002))10)(1.002)=P(1.002)^310(1.002)^210(1.002)

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0oh wait maybe you get a geometric series for the ten part.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0yeah that formula does look like a geometric series

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0first part is definitely p(1.002)^36

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0lets see what the last one is.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0I think I see now why it is so

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0guess it depends on whether you take out ten pounds at the end. if so you will get 10+10(1.002)+10(1.002)^2+...+10(1.002)^35

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0\[x _{n}=a ^{n} x _{0} +(a ^{n1} +....+a+1)b\]

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0and the last part is a series

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0yeah i think so. i bet this simplifies to get essentially what i wrote at the beginning. if my algebra was good enuf i could do it

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0did you try 1000(1.002)^3610(1.002)^35?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0that gives a positive amount, that cannot be right, the interest is around 2 and you take out 10

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0we can use 1+r+r^2+...+r^35=\[\frac{r^{36}1}{1r}\] with r = 1.002

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0yes that is what I thought too, but isnt the denominator r1 ?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0multiply by ten to get 37.289

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0denominator in this case is .002

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0oh wait my calculation is wrong

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0the answer was something around 700

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0i am off by a decimal

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0\[\frac{(1.002)^{36}1}{.002}=37.289\]

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0according to my calculator.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0multiply by ten to get 372.89

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0according to my brain

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0subtract from 1000(1.002)^36 = 1074.578 rounded

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0gives the correct answer! sweet

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0and i get as a final answer (as they say) 701.68

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0glad we got this worked out even if a couple of false starts

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0maths is like this, try hard and fail a lot
Ask your own question
Sign UpFind more explanations on OpenStudy
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.