Answer
See step by step work for solution.
Work Step by Step
A function is one-one if it assigns two different values to two different inputs.
So, the given function will be one-one if,
a) Two teachers have two different offices. (otherwise two teachers having the same office will be mapped to single office which means function is not one-one)
b) There should be only one teacher in a bus to chaperone (otherwise two teachers going in the same bus will be assigned the same bus, which means function is not one-one)
c) Any two teachers do not have the same salary (otherwise two teachers having the same salary will be mapped to the same salary, which means function is not one-one)
d) Two teachers should have different social security number (otherwise two teachers having same social security number will be mapped to the same security number , which means function is not one-one)
