Correct Answer: (b) (21, 11, 11)
Solution:(पहली संख्या - 10) × (दूसरी संख्या - 10) = तीसरी संख्या
(50, 60, 2000) = (50 - 10) × (60 - 10)
⇒ (40 × 50) = 2000
(20, 30, 200) = (20 - 10) × (30 - 10)
⇒ (10 × 20) = 200
इसी प्रकार,
(21, 11, 11): (21 - 10) × (11 - 10)
⇒ (11 × 1) = 11