We need to isolate x in order to find x. However, we need to have common denominators first. Multiply by 30 on both sides. Divide by 5 on both sides to isolate x.
There are 3 odd numbers in a dice which equals 1/2. Then there is 1/6 of a chance of rolling a 3. So it would be 1/2 + 1/6=4/6 which simplifies to 2/3.