.
In all, there are 3 + 5 + 7 = 15 marbles.
The probability under the question is
P = = = = = = 0.2 = 20%. ANSWER
The formula is self-explanatory.
For simple and simplest problems of Elementary Probability theory see the lessons
- Simple and simplest probability problems
- Solving probability problems using complementary probability
- Elementary Probability problems related to combinations
- A True/False test
- A multiple choice answers test
- Typical probability problems from the archive
- Experimental probability problems
in this site.
Also, you have this free of charge online textbook in ALGEBRA-II in this site
- ALGEBRA-II - YOUR ONLINE TEXTBOOK.
The referred lessons are the part of this online textbook under the topic "Solved problems on Probability".
Save the link to this textbook together with its description
Free of charge online textbook in ALGEBRA-II
https://www.algebra.com/algebra/homework/complex/ALGEBRA-II-YOUR-ONLINE-TEXTBOOK.lesson
into your archive and use when it is needed.
Consider these lessons as your textbook, handbook, a Solutions Manual, tutorials and (free of charge) home teacher.
Happy learning (!)