Question

Rahul practices the trumpet every 6th day and flute every 7th day. Rahul practiced both the trumpet and flute today.
How many days until Rahul practices the trumpet and flute again on the same day ?

• A. 28
• B. 32
• C. 38
• D. 42

Answer 1

The correct option is D 42

Rahul practices trumpet every 6th day
Multiples of 6= 6, 12, 18, 24, 30, 36, 42, 48, 54, 60
Rahul practices flute every 7th day
Multiples of 7= 7, 14, 21, 28, 35, 42, 49, 56, 63, 70
We see that that the first common multiple is 42
Mathematically we say that 42 is the least common multiple of 6 & 7.
It will be 42 days until Rahul practices the trumpet and flute again on the same day.