To find the difference between the numbers, she must add the values of the spaces between 3/10 and 1, and between 1 and 1 3/5
we can see this in the image:
The mistake she made is that the first distance is 7/10, not 3/10, and thus, the distance is the sum:
![(7)/(10)+(3)/(5)](https://img.qammunity.org/2023/formulas/mathematics/college/5wxk104ogxbosqf9f7xjeny1o4nfvluqxy.png)
The highlight of the mistake is:
which gives us the result:
![(7)/(10)+(3)/(5)=(7)/(10)+(6)/(10)=(13)/(10)](https://img.qammunity.org/2023/formulas/mathematics/college/87xl8jlyrxeq4ztyvc5ebgljne3x7fcwkn.png)
Answer: 13/10