The initial amount of bacteria is 50.
In 12 minutes, bacteria doubles.
So, the amount of bacteria after first 12 minutes is,
![50*2=100](https://img.qammunity.org/2023/formulas/mathematics/college/lsd955sfslplsl0nhf01uc580ce1k8hgxq.png)
After the next 12 minutes, the amount of bacteria is,
![100*2=200](https://img.qammunity.org/2023/formulas/mathematics/college/ck86kyu35lbvdppp10s1ydtxwimps2glj7.png)
Again, after the next 12 minutes, the amount of bacteria is,
![200*2=400](https://img.qammunity.org/2023/formulas/mathematics/college/npfr99g5ymwpqzyf5avbqygavewmvrkjnn.png)
Again, after the next 12 minutes, the amount of bacteria is,
![400*2=800](https://img.qammunity.org/2023/formulas/mathematics/college/mypiswua5qsbvrrd9sptrcvv9rgf72ziaw.png)
Now, the total time taken is 12+12+12+12=48 minutes.
Therefore, after 48 minutes, the amount of bacteria is 800.