Corona and exponential growth, when does it all end?

Allowing for heavy rounding-up, I was playing with the maths of Covid-19 in the UK. Jan 1st, no. of cases: 0, chance of infection: near to zero Feb 1st, no. of cases: ~ 2, chance of infection: 33 million to 1 Mar 1st, no. of cases: 36, chance of infection:...