Question

what should be added to 6 6/15 to get 8 1/5

Answer 1

let us assume the no. added to be is x
therefore 66/15+x=81/5
x=81/5-66/15
x=243-66/15
x=177/15
x=59/5

Answer 2

let the number be x. 6 6/15=96/15. 8 1/5=9/5. 96/15 + x =9/5. x=9/5-96/15=27-96/15=-42/15. there fore x=-42