Nav Computer: Heading 301ºM, variation 5ºW = 296ºT, Track 315ºM, variation 5ºW = 310ºT, groundspeed: 50nm in 12 minutes = 25nm in 6 minutes = 250kts.  

Centre dot on TAS (225kts), heading (296ºT) under HEADING index, mark where drift (14º Stbd) crosses groundspeed (250 kts).  

Rotate to put mark on centreline under centre dot and read wind, 190ºT/63kts.