Tiger FIFO SYSTEM

Hi assuming I have bought

STOCK A 2 shares @ $10
STOCK A 5 shares @ $11
STOCK A 12 shares @ $13.50

My average is 12.4736 (237/19)

Assuming current Stock A priced at $15

Unrealised PnL will shows $2.5264 (PROFIT)

Correct so far ?

Using FIFO LIFO System in Tiger brokers .

Let say I am selling off 2 shares

Means my capital gain is $10 correct ?

Selling next 5 shares I earn $20

Selling last 12 shares I earn $18

Total I earned is $48

AM I RIGHT the calculation??

Please omit the commission fee cause I am trying to understand the mechanism here.