SBR kit 2018-2019 Q13 Zippy

(vi) On 1 January 20X6, Zippy entered into a contract to sell 10,000 units of a new product,the Whizoo, to a customer for $1,000 per unit. It was agreed that if the customer ordered an additional 5,000 units, a volume discounted price of $950 per unit would apply.

6,000 units were manufactured and delivered in the four months to 30 April 20X6. The customer placed the order for another 5,000 units on 31 March 20X6.

Minor defects were discovered in the first 6,000 units due to an error in the manufacturing process and it was agreed that a credit note of $40 per unit would be issued as compensation. Zippy and the customer agreed to net this amount off against subsequent payments for future orders.

A further 7,000 units had been manufactured and delivered by 30 June 20X6 without any defects. Zippy has included $6 million in revenue (6,000 x $1,000) for the first 6,000 units but has not recorded any additional revenue, as the directors are unsure of the correct accounting treatment.

Hi Sir, does zippy in total purchased for 6k + 5k+ 7k = 18k units??
And how the 2k units came from, which minus which?
Also, in order to arrive at $972 per item, they took 4k + 5k, but how does this in relevant to 7k units?

Also, in note 3, the net assets : $118m + ($48m x 9/12) = $154m.
Where did the $48m came from?

Besides, in note 5, NCI share of post acq’n retained earning to 31/3/20×6
($154m- $114m)x40% =$16m.

Why has to take $154m to subtract the $114m??