How long did each ice age last?

Question

How long did each ice age last?

Answer 1

One was about 200 million years, another one was like 30 million years.

For more info I suggest the wiki http://en.wikipedia.org/wiki/Ice_age

Answer 2

Many glacial advances and retreats have occurred during the last billion years of Earth history. These glaciations are not randomly distributed in time.Instead, they are concentrated into four time intervals. Large, important glaciations occurred during the late Proterozoic (between about800 and 600 million years ago), during the Pennsylvanian and Permian (between about 350 and 250 million years ago), and the late Neogene toQuaternary (the last 4 million years). Somewhat less extensive glaciations occurred during portions of the Ordovician and Silurian (between about 460 and 430 million years ago).