Explanation:

1. a − b < a − c
=> b − c > 0 …........................(i)
As, b is negative real number and c is positive real number, then Eq. (i) is not true.
2. If a < b,when a and b are negative real numbers and c is a positive real number, then a/c a .
3.1/b < 1/c  is always true, as c is a positive real number and b is a negative real number.