8000 blood donors were registered with a Samarpan Blood Bank.Some student organizations started mobilising people for this noble cause..As a result,the no. of donors registered increased at the rate of 20% per half year..FInd the no. of new registrants during 1 1/2 years.

Rate of increasing number of donors per half year = 20%

So, number of new registrants after 6 months = $8000\times \frac{20}{100}=1600$

So total number of registrants after 6 months = 8000 + 1600 = 9600

Then number of new registrants after one year = $1600+9600\times \frac{20}{100}=1600+1920=3520$

So total number of registrants after one year = 8000 + 3520 = 11520

Then number of new registrants after one half year = $3520+11520\times \frac{20}{100}=3520+2304=5824$

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