Is there a natural way to say:<br/><br/>(a) I would like to join both <span style="color:#4040ff;">Mental Arithmetic classes and computer classes</span> since I'm poor in Mathematics and I enjoy playing games on the computer. <br/><br/>(b) I would like to join both <span style="color:#4040ff;">Mental Arithmetic and computer classes</span> since I'm poor in Mathematics and I enjoy playing games on the computer