How many litres of water will a cylindrical pipe hold if it is 1m long and 7cm in diameter

Answer 1

πr^2 h = π*3.5^2 * 100 cm^3 = 3848 cm^3 = 3.848 L
or, since 1L = 1 dm^3, if we use those units,
π*0.35^2*10 dm^3 = 3.848 dm^3

Answer 2

So simple