Answer:
in 33 days
Step-by-step explanation:
Trumpet practice is every 11 days. Flute practice is every 3 days.
You need the Least Common Multiple (the LCM) of the two numbers, 3 and 11.
Since 3 and 11 are prime, the LCM of 3 and 11 is their product.
LCM = 3 * 11 = 33
Answer: in 33 days
You can also solve this by listing multiples of 3 and 11 until you find the smallest number that is a multiple of both 3 and 11.
Multiples of 3: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, ...
Multiples of 11: 11, 22, 33, 44, ...
The smallest multiple of both 3 and 11 is the smallest number that shows in both lists. It is 33.