Question 1101480
Grade level and age are not the same thing but are related and depend on where a person lives.  If grade 0 (kindergarten) is age 5, then grade 3 would be age 8.

<pre>
Children             Age (possibly)

youngest               8

3 in the triplet      16-4=12

oldest                16
</pre>

Product of all five of these ages:  {{{8*12^3*16=221184}}}------perfect match to description.