The red blood cells in a blood sample grows by 10% per hour in first two hours, decreases by 10% in next one hour, remains constant in next one hour and again increases by 5% per hour in next two hours. If the original count of the red blood cells in the sample is 40000, find the approximate red blood cell count at the end of 6 hours.

Original count = 40,000

In the next 2 hours, it increases by 10%

=> Blood cell count after 2 hours = $$40,000(1+\frac{10}{100})^2=40,000(\frac{11}{10})^2$$

= $$40,000\times\frac{121}{100}=48,400$$

It decreases by 10% in next hour

=> Blood cell count after 3 hours = $$48,400(1-\frac{10}{100})^1$$

= $$48,400\times\frac{9}{10}=43,560$$

It remains constant in the next hour, => Blood cell count after 4 hours = $$43,560$$

In the next 2 hours, it increases by 5%

=> Blood cell count after 6 hours = $$43,560(1+\frac{5}{100})^2=43,560(\frac{21}{20})^2$$

= $$43,560\times\frac{441}{400}=48,024.9\approx48,025$$

=> Ans - (C)