Question

A bacteria culture begins with 4 bacteria which double in size every hour. How many bacteria exist in the culture after 8 hours?

Answer 1

It begins with 4

After 1 hour= 4 x 2= 8
         2 hours= 8 x 2= 16
         3 hours= 16 x 2= 32
         4 hours= 32 x 2= 64
         5 hours= 64 x 2=128
         6 hours= 128 x 2=256
         7 hours= 256 x 2= 512
         8 hours= 512 x 2= 1024

Answer: 1024

Answer 2

After one hour: 8
after 2 hours: 16
after 3 hours 32
after 4 hours 64
after 5 hours 128
after 6 hours 256
after 7 hours 512
 after 8 hours 1024