Multiple dotnet core versions on linux docker image

I want to know how i can run and install multilple version of the dotnet core framework 2.1 and 1.1 in a docker container on linux. Below is my current dockerfile and i want to add dotnet 1.1 to it as well

FROM microsoft/dotnet:2.1.403-sdk-bionic

ENV DOTNET_SKIP_FIRST_TIME_EXPERIENCE true
ENV DOTNET_CLI_TELEMETRY_OPTOUT true

RUN apt-get update && 
    apt-get install -y zip  

Source: StackOverflow