How many iron rods, each of length 7 mts and diameter 2 cms can be made out of 0.88 cubic metre of iron ?

Given length of iron rod =7 mts and  and diameter of rod = 2 cms 

=> r = 1/100 mts

Therefore,  Volume of one rod =  $\mathrm{\pi r}2h$ cu. m =   $\frac{22}{7}\times \frac{1}{100}2\times 7$cu. m =  $\frac{11}{5000}$ cu. m

Given volume of iron = 0.88 cu. m 

Therefore, Number of rods =  $0.88\times \frac{5000}{11}$ = 400.