Open tution Revision mock exam

The share price of CP Plc is $4 per share. they annouce a 1 for 5 rights issue at $3.10 per share. What % of the rights offered to a shareholder does a shareholder need to take up so as to have no net cash flow resulting from the issue? Answer given is 19.48% Kindly explain how is it calculated. P.S I am unable to view the mock exam screen fully and some options are down but i cannot scroll down the window on that page. I have ried zoom out also but it didnt help.