To find the answer test all the possible solutions
6x+(5x+10)
= 6x+5x+10
=11x+10
A) 11x+10
B) (6x+10)+5x
= 6x+10+5x
=11x+10
C) 5(x+10)+5x
= 5x+50+5x
= 10x+50, this is not equivalent.
D) 6x+5(x+10)
= 6x+5x+50
= 11x+50, this is not equivalent either
For a number to be divisible by 6, it must also be divisible by 2 and 3. Therefore, we need to check if a number is even and then check if the sum of the digits is divisible by 3.
3 periods, 20 minutes each
20 * 3 = 60 minutes
12 minutes per period
12 * 3 = 36
So the ratio is 36:60, or simplified: 3:5
