Answer:
180
Step-by-step explanation:
30 = 2 x 3 x 5
45 = 3^2 x 5
60 = 2^2 x 3 x 5
90 = 2 x 3^2 x 5
LCM ( 30, 45, 60, 90 )
= 2^2 x 3^2 x 5
= 4 x 9 x 5
= 180
