The cash price of a 70 inches TV is $7,000. Mr Tan bought the TV on hire purchase by putting a downpayment of $1,000 and monthly instalments of $150 over y months.

Express the total amount payable by hire purchase, in terms of y.

Express, in terms of y, the amount Mr Tan could have saved if he had paid in full by cash.

Given that the seller charged simple interest at 10% per annum, form an equation to calculate the value of y.