Solve for u. 126 = 6u a.) 6 b.) 21 c.) 20 d.) none of the above

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!