Marbles of diameter 1.4 cm are dropped into a beaker containing some water are fully submerged. The diameter of beaker is 7 cm. Find how many marbles have been drapped in it if the water rises by 5.6 cm.
Volume of water that rises in putting marbles in the beaker.
= π(7/2)^{2} × (5.6) cu cm.
Volume of one marble = 4/3π(0.7)^{3} cu cm.
∴ Number of marbles = π(7/2)^{2} × 5.6/4/3π(0.7)^{3} = 150