First we find how many cookies Betty will eat in a week by multiplying her daily amount by 7, meaning 7*3=<<21=21>>21 cookies eaten in a week.
We repeat this for the brownies, finding she eats 7*1=<<7*1=7>>7 brownies in a week.
We subtract the 21 cookies from the original amount of 60, finding 60-21= <<60-21=39>>39 cookies remaining.
We repeat this step for the brownies, finding 10-7= <<10-7=3>>3 brownies remaining.
In the end, therefore, Betty has 39-3= <<39-3=36>>36 more cookies than brownies.
#### 36