John took all his money from his savings account. he spent $110 on a radio and four elevenths 4 /11 of what was left on presents for his friends. john then put two fifths
2/5 of his remaining money into a checking account and donated the $420 that was left to charity. how much money did john originally have in his savings account?

Abank manager wants to encourage new customers to open accounts with principals of at least $2,500. he decides to make a poster advertising a simple interest rate of 3%. what must the principal be if the bank manager also wants to advertise that one can earn $10 the first month? can the poster correctly say, "open an account of $2 comma 500 and earn at least $10 interest in 1 month! "?