Answer:
The probability that she uses gray or yellow is 0.93
Explanation:
Suppose,
,
and
represent the events of using gray, blue and yellow colors respectively.
So,
and
![P(Y)= 0.75](https://img.qammunity.org/2019/formulas/mathematics/middle-school/rd70mmg5civ2jaa5slgi4mm369se89tvje.png)
The probability that she uses gray and yellow is 0.62 , that means
![P(G \cap Y)= 0.62](https://img.qammunity.org/2019/formulas/mathematics/middle-school/dvag2ayazu142vxanu70xes71q95dz45vl.png)
The formula we will use here:
![P(G\cup Y)= P(G)+P(Y)-P(G\cap Y)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/nw0ohw8g9scno5aju1hr1ndwkt761rgu4s.png)
According to the above formula.....
![P(G \cup Y)= 0.80+0.75-0.62\\ \\ P(G\cup Y)= 0.93](https://img.qammunity.org/2019/formulas/mathematics/middle-school/6ujujr0xn06p2na1n8p6l4vwpfaqar2yvo.png)
So, the probability that she uses gray or yellow is 0.93