Question
A hollow cylindrical pipe is made of iron. The
difference between the outer and inner curved surface area is 176 cm². The height of the pipe is 28 cm, and the sum of the inner and outer radius is 30 cm. Find the total surface area of the hollow cylindrical pipe.Solution
We have -2 π h (R-r) = 176 = 2×22/7×28(R-r) =176 R-r = 1 Also given – R + r = 30 Then – R = 15.5cm, r = 14.5cm. So, the total surface of the hollow cylinder = 2 π h(R-r) +2 π (R2-r2) =2 π (R +r) [h +R-r] =2×22/7×30(28+1) =2×22/7×30×29 =38280/7  =5468.5cm2
What will come in place of the question mark (?) in the following series?
20, ?, 30, 60, 150, 450
-1, 5, 23, 59, ?
Find the missing number in the given number series.
2, 5, 11, 23, 47, ?48, 24.5, ?, 39.75, 81.5, 206.25, 621.75
What will come in place of the question mark (?) in the following series?
24, 36, 16, 46, 4, ?, -12Â
What will come in place of the question mark (?) in the following series?
146, 122, ? , 74, 50, 26
660, 653, 639, 618, 590, ?
65, 90, 140, ?, 315, 440
64, 66, 69, 74, 81, ?
- What will come in place of the question mark (?) in the following series?
10, 17, 26, 37, 50, ?
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