Respuesta :

syrah1331
The answer is is b) 10
401211
none, but 7 is not a common factor of 15,45,and 90

think about it. 

3 x 5=15   <<== that already eliminates it

5 x 3= 15  <<== that also eliminates it

10 x 9= 90 <<== eliminated

15 x 1= 15 <<== so all of them are eliminated as an answer