A bag contains 5 red balls, 10 blue balls and 15 green balls. Three balls are drawn from the bag one after another without replacement. The event

**R1**,

**R2**,

**B2**and

**G3**are defined as follows.

**R1**- represents the event the first ball drawn is red.

**R2**- represents the event the second ball drawn is red.

**B2**- represents the event the second ball drawn is blue.

**G3**- represents the event the third ball drawn is green.

Find

a) i) P(

**R1**[tex]\cap[/tex]

**R2**)

for this , i drew a tree diagram, for it to be red for the first ball, it has to be 5/30 and for the second to be red it has to be 4/29 thus multiplying them both would give me the answer which is 2/87.

ii) P(

**R1**[tex]\cup[/tex]

**R2**)

for this i thought of P(

**R1**) + P (

**R2**) - P(

**R1**[tex]\cap[/tex]

**R2**) would solve the problem but the answer is incorrect and later i see, i don't really know what's the probability of

**R2**because it could be 5/29 or 4/29.

Please help.