Question
Volume of material used in constructing a hollow
cylinder of height 24 cm and thickness 1 cm is 96Ï€. What is the sum of the internal and external radii?Solution
Let external and internal radius of the cylinder be R and r cm respectively. Thickness of cylinder (R - r) = 1 cm. Height of the radius h = 24 cm As we know, Volume of hollow cylinder = π (R2 – r²) h π (R2 – r²) h = 96π  π (R + r) (R - r) h = 96π  (R+ r) x 1 x 24 = 96  (R+ r) = 96/24  (R + r) = 4 cm
2Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 4Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 5Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 19Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 70...
6000 3002 1503 ? 378.75 191.375 97.6875
...If  204    196       223   x  284
Then, what is the average of the numbers of the above series?
...8   24    12    ?   18     54
3 ? 7 16 71 346
...104   106   110   113   ?   126
12, 18, 28, 42, 52, ?
18Â Â Â Â Â Â Â Â Â Â Â Â 29 Â Â Â Â Â Â Â Â Â Â Â Â Â Â 51 Â Â Â Â Â Â Â Â 84 Â Â Â Â Â Â Â Â 128 Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 182
5, 8, 17, ?, 37, 48
(32.03 + 111.98) ÷ 18.211 = 89.9 – 20.23% of ?