कोई धनराशि चक्रवृद्धि ब्याज से 2 वर्ष मे रुपए 4500 तथा 4 वर्ष बाद रुपए 6750 हो जाती है, तो राशि क्या है -

Options

A. रु 4000
B. रु 2500
C. रु 3000
D. रु 3050

Answer

c

Explanation

(c) Amount `(A_(1))` = Rs. 4500,
`t_(1) = 2 "years"`
Amount `(A_(2))` = Rs. 6750,
`t_(2) ` = 2 years
Let Rate % = R% ,
Principal = Rs. P According to the question ,
Case (I) : 4500 = `P(1 + (R)/(100))^(2)………..(i)`
Case (II) : 6750
`= P(1+(R)/(100))^(4)............(i)`
By dividing equation (ii), by equation (i) (समीकारण (ii ) को समीकारण (i ) से भाग करने पर ) `= (6750)/(4500) = (1+(R)/(100))^(2)`
`(3)/(2) = (1 +(R)/(100))^(2)........(ii)`
From equation (i) `4500 = P xx(3)/(2)`
P = Rs. 3000
Hence Required principal
Alternate
Note : In such type of question to save your valuable time follow the given below method .
( नोट : इस प्रकार के प्रशनो मे अपनी बहुमूल्य समय के बचत के लिए आप नीचे दी गयी विधा का प्रयोग कर सकते है |)
Let principal = Rs. P
According to the question

`Pxx(3)/(2) = 4500, P = (4500xx 2)/(3)`
=Rs. 3000
Hence required principal
Rs. 3000