Answer:

Explanation:
Let us assume that the third commerical played time be x .
As given
Three commercials are played in a row between songs on the radio.
 The three commercials fill exactly 3 minutes of time. 

i.e 

Thus equation becomes 

L.C.M of (6,5) = 30


35 + 18 + 30x = 3 × 30 
35 + 18 + 30x = 90
30x= 90 -53 
30x = 37

Or

