RRB JE practice question
A solid right circular cone of base radius 9 cm and height 32 cm is melted and recast into a solid right circular cylinder of base radius 6 cm. Find the height of the cylinder.
From a RRB JE Quantitative Aptitude practice set · Quantitative Aptitude
Tap an option to check your answer.
Show answer and explanation
Correct answer: (D) 24 cm
Volume is conserved: (1/3)πr²h = πrc²hc ⇒ hc = r²h/(3rc²) = (9²×32)/(3×6²) = 2592/108 = 24 cm.
हिंदी में प्रश्न
9 सेमी आधार त्रिज्या और 32 सेमी ऊंचाई वाले एक ठोस लम्ब वृत्तीय शंकु को पिघलाकर 6 सेमी आधार त्रिज्या वाले एक ठोस बेलन के रूप में ढाला जाता है। बेलन की ऊंचाई ज्ञात कीजिए।
उत्तर जाँचने के लिए किसी विकल्प पर टैप करें।
उत्तर और व्याख्या देखें
सही उत्तर: (D) 24 सेमी
आयतन संरक्षित रहता है: (1/3)πr²h = πrc²hc ⇒ hc = r²h/(3rc²) = 2592/108 = 24 सेमी।
More solved Quantitative Aptitude questions
- Simplify: 12 x 9 - 8 / 4 + 4 = ?
- Two trains cover the same distance between two stations. The ratio of their speeds is 3 : 4, and the first train takes 2 hours more than…
- A trader marks his goods x% above the cost price. He then allows two successive discounts of 20% and 10% on the marked price. If he still…
- A train covers 80 km at a certain speed and then covers the next 120 km at a speed 20 km/h more than the first. If the total time taken is…
- The four angles of quadrilateral EFGH, taken in order at vertices E, F, G, H, are in the ratio 2:3:5:8. Find angle H.
- Find the volume of a cuboid with length 8 cm, breadth 6 cm, and height 5 cm.