Consolidated Statement of Financial Position

Hello
Could you please help me with the below question?

At the 1st of January 20×2 Y acquired 75% of the share capital of Z for $400,000. At that date the share capital of Z consisted of 600,000 ordinary shares of 50c each and its reserves were $50,000.
The fair value of NCI at the date of acquisiton was $100,000.

What amount should appear for goodwill int eh consolidated statement of finan position of Y and its subsidiary z at 31 december 20×6

a) 150000
b) 137,500
c) 55,000
d) 110,000

The correct answer is A, below the calculation

Cost of investment 400,000
NCI acquisition 100,000
Less NA acquistion (350,000)

150,000

I didn’t undestand how NA acquistion 350,000 was calculated.

Thanks
Gabbi