What is the largest number of pipes of the shape of right circular cylinders with length 10 cm. and radius 1 cm. that can be fitted into a box, all of whose sides are 20 cm. in length? 10 सेमी. लम्बी और 1 सेमी. त्रिज्या की सम वृत्तीय बेलनाकार की कितनी पाइपों को एक बॉक्स में रखा जा सकता है, जिसकी सभी भुजाओं की लम्बाई 20 सेमी. है?

The box is a 20cm × 20cm × 20cm cube with volume 8000 cm³. Each pipe is a cylinder with length 10cm, radius 1cm, so volume = π(1)²(10) = 10π ≈ 31.4 cm³. If we could pack perfectly with no wasted space, maximum pipes = 8000/31.4 ≈ 255 pipes. However, cylindrical packing efficiency in a rectangular box is much less than 100% due to gaps between cylinders. Options A (800), B (400), and C (200) all assume unrealistic packing scenarios. The actual maximum is significantly less than 200, making 'None of these' the correct answer.