Answer: He will practice both on every 15 days.
Step-by-step explanation:
Given: Jaquan practices soccer every 3 days.
He practices basketball every 5 days Jaquan practiced both today.
The number of days until he practices both = Least common multiple of 3 and 5
= 3 x 5 [Both are primes]
= 15
Hence, he will practice both on every 15 days.