Which describes the two parts of a measurement? a unit and a symbol a conversion factor and a number a symbol and a conversion factor a number and a unit

The measurement consists in comparing a selected pattern with the object or phenomenon whose physical magnitude is going to be measured, to find out how many times the pattern is contained in that magnitude. That is, it is about identifying or quantifying a particular characteristic or aspect of a particular object or construct.

Now, a well done measurement has two parts:

-The number gives us information about the quantity of the measurement, or in other words, the magnitude of the measurement and its precision.  

-The units gives us information about the property that is being measured. This is quite important, because a measurement or result with no units is useless.

Note the units may be expressed with letter or symbols, depending on what we are measuring.

if the person is shown to have +90n, then ans is -10n.

if the person is shown to have -90n, then ans is +10n.