A total of 180 marbles (gray, white, and black) are placed in a line. If the first five are gray, followed by four, followed by three black, followed by five gray, followed by four white, followed by three black,... If this pattern continues, what is the color of the 158th marble in this line?

Answer 1

Did you leave out the word "white" after the first word "four" ?

Note that after each twelve marbles, the cycle repeats. Therefore after 156 (12x13) , #157 will be the samd as #1 etc.