Assume that life on Earth began 3.5 billion years ago. To the nearest percent, how much of this time have anthropoids been living?

Anthropoids lived for approximately 0.86% of the total time.

Explanation:

Anthropoids are the higher developed organisms that includes apes and ape mans. The age of earth is 3500 million and anthropoids lived for about 30 million years. By the simple calculations we can find out the data in percent which gives us the result nearest to 0.86%. That means 0.86% of 3.5 billion year is equivalent to 30 million years (time that was lived by anthropoids).