Respuesta :
Answer:
1
Step-by-step explanation:
Listing the factors of the 4 numbers
factors of 3 : 1, 3
factors of 5 : 1, 5
factors of 9 : 1, 3, 9
factors of 15 ; 1, 3, 5, 15
The common factor is 1
Thus the HCF is 1
Numbers which have no common factor other than 1 are said to be co- prime
