Please help! Joanne is investing $13 600 in an account that pays 8.2% per annum, compounded monthly. A friend has agreed to sell her a second-hand pick up truck for her landscaping business for $15 900. She will need to pay the government GST (15%) on the price of the truck. a) How long will it take, to the nearest month, to have enough in the account to buy the truck? b) How many months sooner, to the nearest month, could she buy the truck if the interest rate went up to 9.3% per annum, compounded monthly?

Question

anonymous · Answer

I don't know how to find the time for this problem D:

anonymous · Answer

Try using the formula Interest = Principal * Rate * Time

anonymous · Answer

so she needs to pay 15900 * 1.15 (to count the tax) which is 18285

mertsj · Answer

No, emmy.  This is a compound interest problem, not simple interest.

anonymous · Answer

then you know that she will have 13600 * 1.082^(x) after x months

anonymous · Answer

so you solve for x

mertsj · Answer

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