To solve the equation, we can follow the steps below:

1/2 4/5 x/3 + 1/15 = 1

First, let's simplify the left side of the equation:

1/2 4/5 = 1/2 4/5 = 4/10 = 2/5

(2/5) * x/3 = 2x / 15

Now, our equation looks like this:

2x / 15 + 1/15 = 1

Combine the fractions on the left side:

(2x + 1) / 15 = 1

Now, we can multiply both sides by 15 to get rid of the fraction:

2x + 1 = 15

Subtract 1 from both sides:

2x = 14

Divide by 2:

x = 7

Therefore, the answer is б) 1.