Calculation of rate of learning (Unlike before) and optimal pricing !

The Q organisation is a large worldwide respected manufacturer of electronic goods.
Q constantly develops new products that are in high demand.
Market research has discovered that the price-demand relationship for a new DVD recorder product during the initial launch phase will be as follows:

Price($) Demand(units)
100 10,000
80 20,000
69 30,000
62 40,000

Production of the DVD recorder would occur in batches of 10,000 units and the production director believes that 50% of the variable manufacturing cost would be affected by a learning curve. This would apply to each batch produced and continue at a constant rate of learning up to a production volume of 40,000 units when the learning would be complete. The production director estimates that the unit variable manufacturing cost of the first batch would be 60$( $30 of which is subject to the effect of learning curve, and $30 of which is unaffected), whereas the average unit variable manufacturing cost of all four batches would be $52.71.

There are no non-manufacturing variable costs associated with the DVD recorder.

Required
(a). Calculate the rate of learning that is expected by the production director. (2marks)

(b). Calculate the optimum price at which Q should sell the DVD recorder in order to maximise its profits during the initial launch phase of the product. (8marks)

I can’t make out to the suggested answer to this question.. That’s why i have posted this question here as i want your fine guidance on this question.

Cheers : )