Question

There are 7 red, 8 blue, and 11 yellow balls. What is the probability of choosing either one yellow or red ball?  
1. 7/13
2. 9/13
3. 11/26
4. 9/26
5. 10/13

Answer 1

Correct Answer - Option 2 : 9/13

GIVEN:
Red balls = 7 

Blue balls = 8

Yellow balls = 11

CONCEPT:

For 'either or' adding function is applied.

FORMULA USED:

P = Number of favorable outcomes/Total number of outcomes

CALCULATION:

Total balls = 7 + 8 + 11 = 26

Either red or yellow = 7 + 11 = 18

∴ P = 18/26 = 9/13

∴ The probability is 9/13