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.
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
Statement: D < E < F ≥ G; D ≥ H > I
Conclusion: I. F > IÂ Â Â Â Â II. F = I
If '>' denotes '+', '<' denotes '-', '-' denotes '×', '×' denotes '÷', '÷' denotes '=', then choose the correct statement of the following.
...Statements: A @ B, B # C, C % D
Conclusions: a) A # CÂ Â Â Â Â b) A @ DÂ
Statements: B ≤ C < E; D ≤ F ≤ G; E = D; A > B
Conclusions:
(i) E ≥ G
(ii) A < E
(iii) B ≤ G
(iv) C < F
Statement: D > A ≥ R = B ≤ M < U
Conclusions:
I. U > R
II. D ≥ M
Statements: F ≥ G > H; I < J ≤ H; J > K
Conclusions:
I. F > J
II. K < G
III. H > K
In which of the following expressions will the expression ‘ Q > B ’ be definitely true?
Statements: D % E, E & A, A @ B, B # C
Conclusions: I. C & AÂ Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â II. D # B
...Statements: K * D, D $ N, N % M, M © W
Conclusions: Â Â Â Â Â I.M % WÂ Â Â Â Â Â Â Â Â Â Â Â Â Â II.M $ WÂ Â Â Â Â Â Â Â Â Â Â Â Â III.N @ DÂ...
Statements: P > Q ≤ R; Q ≥ O > S; T < S ≤ U
Conclusions:
I. T < R
II. U ≤ Q
III. P > U
...
