Step 1 — speed to miles per minute. Ground speed ÷ 60 = miles per minute (mpm).
Easy anchor: 60 kt = 1 mpm, so 240 kt = 4 mpm, 480 kt = 8 mpm. (30 kt = ½ mpm.)

Step 2 — the triangle. Distance = mpm × minutes. Cover the one you want:
• Distance = mpm × time   • Time = distance ÷ mpm   • Speed = distance ÷ time

Wind first (Tower). Ground speed = true airspeed ± wind. Tailwind adds, headwind subtracts. Work out the ground speed, then do Steps 1 & 2.