Terribly stuck! How does one read a z-table 'backwards'?!

In one question, I'm required to find a value z*, such that $\displaystyle P(Z<z*)= 0.98$ and $\displaystyle P(0<Z<z*)= 0.48$ -- by reading the table 'backwards'.

And in the next one, in order to find $\displaystyle z_{a/2}$, I need to do the same.

Any help would be greatly appreciated!