7. To pump water from a water reservoir 3 m deep and maximum water level at 135 m, a pump is installed to lift water up to R.L. 175 m at a constant rate of 36, 00, 000 litres per hour. If the length of the pipe is 1506 m and f = 0.01, ignoring other minor losses and assuming the economical diameter from Lea's formula D = 1.2 Q, the water horse power of the pump is
10. If P is population of a city in thousands and Q is fire demand in litres per minute, for proper estimate of water, the Empirical formula is suggested by