At most, how many one sixth 1 6-inch-long pieces of string can you cut from a two thirds 2 3-inch-long piece of string?

The first week samantha learned to read braille, she could read 10 words per minute. in the second week she increased her speed by 20%. in the third week she increased her speed again by another 25%. how many words could she read per minute by the third week? hurry and tell me!