230k views
1 vote
Help on this math problem plz: You have piano lessons every seventh day and cooking lessons every fourth day. Today you have both lessons. In how many days will you have both lessons on the same day again?

User Hudson
by
5.8k points

2 Answers

7 votes
In 28 days, you will have both lessons on the same day again.
User Daniel Kereama
by
6.1k points
2 votes

Answer: 28 days

Explanation:

Given : You have piano lessons every seventh day and cooking lessons every fourth day.

The number of days it takes to have both lessons on the same day will be the least common multiple of 7 and 4.

Using prime factorization,


7=7*1\\\\4=2*2

LCM(7,4)=
7*2*2=28

Hence, if today you have both lessons then after 28 days you will have both lessons on the same day again.

User Benophobia
by
5.6k points