Given,
Count of bacteria in sample = 13125000
According to increase and decrease of growth rates,
Let count of bacteria after 3 hours = X
So,
= 13125000\(({1}+\frac{10}{100})({1}-\frac{8}{100})({1}+\frac{12}{100})\) = x
= 13125000\(\times\frac{11}{10}\times\frac{23}{25}\times\frac{28}{25} = x\)
\(= x=\frac{1312500 \times 10 \times 25 \times 25}{11 \times 23 \times 28}\) = 14876400
Hence,
Count of bacteria after 3 hours will be = 14876400