Question 1122574
.
The solution by @josmicely is INCORRECT, 


so I came to write it CORRECTLY:



<pre>
Let a = the grandson’s age

Freddy’s age is 8a + 4

The sum of their ages <U>IS GREATER TNAN  67</U>.

a + 8a + 4 > 67 

9a > 63 

a > 7


The youngest the grandson can be is 8.
</pre>