This is an alternating pattern series. Odd positions (1st, 3rd, 5th): 2.7, 3.6, 4.8 increase by ×4/3 each time (2.7×4/3=3.6, 3.6×4/3=4.8). Even positions (2nd, 4th, 6th): P, 2.4, 3.2 also follow ×4/3 pattern (P×4/3=2.4, so P=1.8; 2.4×4/3=3.2). Option B (1.8) is correct.