as we know that If the 4" side of the card was scaled up to 10.5
 then the scaling factor is 10.5/4 = 2.625.Â
The 5 side would  be the length 5 x 2.625 = 13.125 which exceeds the maximum dimension of 11.Â
Thus, it is the 5 side which is scaled up to 10.5Â and the scaling factor is therefore 10.5/5 = 2.1.Â
The scaled up length of the 4 side is thus 4 x 2.1 = 8.4.