Hi Shaunice,

Is that $\left(24^{15}\right) \times 4$ or $\left(24^{15}\right)^4?$ If it's the latter then

\[\left(24^{15}\right)^4 = \left(24^{15}\right) \times \left(24^{15}\right) \times \left(24^{15}\right) \times \left(24^{15}\right)= 24^{60}.\]

In either case you need to find the units digit of a power of 24. For this have a look at a response I gave to Alex's similar question. Write back if you need further assistance.

Penny