মেনু
QB Archive Quiz Creator Graph Poll Mode View Ques Quiz Leaderboard About
থিম নির্বাচন

আপনার পছন্দের থিম বেছে নিন।

Download Address Academy - Best Offline Education App

Instructions: DO NOT USE CALCULATOR. Figures are not drawn to scale. Kalam takes 2 days more than what Zakir takes to produce x chairs. They work together for 6 days and produce 24x chairs. How many days will it take Kalam to produce 2x chairs?

A. 2
B. 4
C. 5
D. 6
E. none of these
DUIBAমানসিক দক্ষতা(IQ)গাণিতিক সমস্যাIQ-4 (Topic Practice)DU - ⚡ অনলাইন প্রশ্নব্যাংক দেখুন 💥
Join Telegram
Explanation: (E) Let \(D_Z\) be the days Zakir takes to produce x chairs, so \(D_K = D_Z + 2\). Work Rate: \(R_Z = \frac{x}{D_Z}\) chairs/day, \(R_K = \frac{x}{D_K} = \frac{x}{D_Z + 2}\) chairs/day. Combined rate: \(R_{Z+K} = \frac{24x}{6} = 4x\) chairs/day. \(R_{Z+K} = R_Z + R_K \implies 4x = \frac{x}{D_Z} + \frac{x}{D_Z + 2}\). Divide by x: \(4 = \frac{1}{D_Z} + \frac{1}{D_Z + 2} \implies 4 = \frac{D_Z + 2 + D_Z}{D_Z(D_Z + 2)} = \frac{2D_Z + 2}{D_Z^2 + 2D_Z}\). \(4(D_Z^2 + 2D_Z) = 2D_Z + 2 \implies 4D_Z^2 + 8D_Z = 2D_Z + 2 \implies 4D_Z^2 + 6D_Z - 2 = 0 \implies 2D_Z^2 + 3D_Z - 1 = 0\). Solving this quadratic equation for \(D_Z\) yields an irrational number. \(D_K = D_Z + 2\) is also irrational. Days for Kalam to produce 2x chairs: \(D_{K(2x)} = D_K \cdot 2 = 2(D_Z + 2)\), which is an irrational number. Since the options are integers, the answer is none of these.

একাউন্টে প্রবেশ করুন

Logo

স্টাডি ট্র্যাকার এবং অন্যান্য প্রিমিয়াম ফিচার ব্যবহার করতে আপনার গুগল একাউন্ট দিয়ে লগইন করুন।