ok here are some maths questions..do as much as u can..thanx for any help.muah!?

[Gerard E]

Q1) John put $y in an investment scheme that pays 6% per annum ( per year ) simple interest.
(a) Find the value of y if the accumulated amount after 5 years is %5200.
(b) Hence, find the value of "n" if the interest earned after "n" years is $2880.


Q2) Josh and Jane each deposit $10,000 in banks A and B respectively. Suppose that bank A pays simple interest of x% per annum, and bank B pays compound interest of y% per annum :
(a) Find the value of x in Josh's accumulated amount after 6 years is $11,800.
(b) Find the value of y if Jane's accumulated amount after 2 years is $10,506.25.
(c) Who has more money in the bank account after 6 years?

Q3) The cash price of a mobile phone is $540. Rui Qi bought the mobile phone by paying $42 monthly instalments over 15 months.
(a) Find:
(i) The total amount payable by Rui Qi,
(ii) The extra amount payable by Rui Qi.

(b) Find the flat rate of interest of the instalments. Give your answer correct to 3 significant figures.

THANX FOR ANY HELP.
OOPS : Find the value of x "IF" Josh's .....