There are 10 less trumpet and saxophone players number of saxophone players three times the number of trumpet players how many trumpet players are there?

Let a be the number of trumpet players
Let b be the number of saxophone players

(1) a = b-10
(2) b =3a

Substitute
(2) into (1)
(1) a =3a-10
(1) 2a =10 

 (1) a = 5and
(2) b = 3(5)(2)
b =  15

There are 5 trumpet players and 15 saxophone player