If two radio stations start conmercials at 10am, when will the stations have commercials at the same time? One station plays every 12 minutes the other every 8 minutes.

If two radio stations start commercials at 10 AM , then at 10:24 AM the stations will have commercials.

Step-by-step explanation:

Given: One station plays every 12 minutes the other every 8 minutes.

The minimum time at which both stations have commercials  = lcm (12 and 8 )

12 = 2 x 2 x 3

8 = 2 x 2 x 2

LCM( 12 and 8)= 2 x 2 x 2 x 3 = 24

The minimum time at which both stations have commercials  = 24 minutes

If two radio stations start commercials at 10 AM , then at 10:24 AM the stations will have commercials.

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional