They meet (or pass) each other two hours after B leaves.
When B starts trip A has already gone 23 miles (46 x 0.5)
This means they are still 220 miles apart.
Their closing speed is 46 + 64 = 110 mph.
They will meet 2 hours after B leaves home. (220 / 110)
A will have travelled 46 x 2.5 = 115 miles and B will have travelled 2 x 64 = 128 miles