There are 7 sheets altogether. 2 of them being 0.0625 so 0.0625+0.0625=0.125, this leaves 5 sheets left over that are 0.125 thick so 0.125 multiplied by 5 equals 0.625. To find the total width add 0.125 and 0.625 which equals 0.75.
0.75 is your final answer