Question
Outer diameter of 20 cm long pipe is 25 cm. If the
thickness of the metal in the pipe is 1 cm. Find the total surface area of the pipe?Solution
Outer part surface area = 2πRh Inner part surface area = 2πrh Area of shaded portion = 2πR² - (πr)² = π(R² - r²) Total surface area = 2πRh + 2πrh + 2π(R² - r²) = 2π(R+r) [h + R - r] = 2π(R+r) [h + thickness] Required surface area = 2π(R+r) [h + thickness] = 2 × 22/7 × (12.5 + 11.5) × 21 = 132 × 24 = 3168
33, ?, 66, 82.5, 99, 115.5
- What will come in place of (?) in the given number series.
5, 10, 8, 16, 11, ?, 17 10296/72 + 3040 = (? × 4) + 1395
What will come in place of the question mark (?) in the following series?
2.5, 6.5, 18.5, 54.5, 162.5, 486.5, ?
6848 + 9215 – 7295 - ? = 5945 – 3244
625, 125, 50, 30, 24, ?
64 32 32 48 96 ?
...17, 36, 65, 104, 153, ?
What will come in place of the question mark (?) in the following series?
112, 123, 144, 169, 190, ?
56, 27, 14.5, 6.25, ?, 1.0625