Question:
If at same rate of interest in 2 years, Simple Interest is ₹42 and Compound Interest is ₹51, then what is the principal (in ₹)?
(a) 44
(b) 49
(c) 42
(d) 53
यदि समान ब्याज दर पर 2 वर्षों में साधारण ब्याज ₹42 और चक्रवृद्धि ब्याज ₹51 है, तो मूलधन (₹ में) क्या है?
(a) 44
(b) 49
(c) 42
(d) 53
Correct Answer: (b)
Explanation:
Detailed Explanation: 1 year SI = 21.
CI – SI for 2nd year = 51 – 42 = 9.
Rate R = (9/21)×100 = 300/7 %.
SI = P×R×T/100 => 42 = P × (300/7) × 2 / 100 => P = ₹49.
विस्तृत व्याख्या: 1 वर्ष का SI = 21
अंतर = 51 – 42 = 9 रुपये
दर R = (9/21)×100 = 300/7%
SI से: 42 = P × (300/7) × 2/100 => P = ₹49।