Answer:
Lessons has Lindsey finished = 21
Explanation:
It is given that,
Joe has finished 14 of the 30 lessons in his piano book. Lindsey has finished the same percent of lessons from her piano book, but her book contains 45 lessons.
To find the percentage of lessons of Joe
Percentage = (14*100)/30 = 140*3 = 46.67%
To find the lessons has Lindsey finished
Lindsey has finished the 46.67% of lessons from her piano book
46.67% of 45 = (46.67*45)/100 = 2100/100 = 21
Therefore lessons has Lindsey finished = 21