[tex]\large\boxed{70/120\,\,(7/12\,\,\text{when simplified)}}[/tex]
In this question, you're trying to find the probability of choosing a button that's either red or blue.
We know that there are:
With the information above, we can find the probability.
We know that there is a total of 120 buttons.
We're trying to find the probability of choosing a red or blue marble, so we would add the amount of blue and red marbles together to get the probability.
[tex]30+40=70[/tex]
We would represent the probability as a fraction.
The probability would be:
[tex]70/120[/tex]
The probability of picking a red or blue marble is 70/120.
When you simplify the fraction by 10, it would be 7/12.
