Question

तीन संख्याएँ, चौथी संख्या का क्रमशः 12-%, 18% तथा 22% है।
। यदि पहली और तीसरी संख्या का योग 690 हो, तो चौथी संख्या क्या​

Answer 1

Step-by-step explanation:

Let the fourth number be x.

$\therefore \: {1}^{st} \: number = x\times 12 \% \: = 0.12x \\ \\ \: \: \: \: \: {2}^{nd} \: number = x\times 18 \% \: = 0.18x \\ \\ \: \: \: \: \: {3}^{rd} \: number = x\times 22 \% \: = 0.22x \\ \\ according \: to \: the \: given \: condition \\ \\ {1}^{st} \: number + {3}^{rd} \: number = 690 \\ \therefore \: 0.12x + 0.22x = 690 \\ \implies \: 0.34x = 690 \\ \implies \: x = \frac{690}{0.34} \\ \implies \: x = \frac{69000}{34} \\ \implies \: x = \frac{34500}{17} \\ thus \: the \: fourth \: no \: is \: \frac{34500}{17}$