A jar consists of blue, red and green marbles. The probability of each of them is 2/7 , 3/k and 5/2k. Find the value of k.

k = 77/10

Step-by-step explanation:

The jar consist of blue, red and green marbles . The probability of each of them can be described as follows.

probability of blue marbles = 2/7

probability of red marbles = 3/k

probability of green marbles = 5/2k

The sum of the individual probability is equals to 1. Therefore,

2/7 + 3/k + 5/2k = 1

collect like terms

(6 + 5)/2k = 1 - 2/7

11/2k =(7 - 2) /7

11/2k = 5/7

cross multiply

10k = 77

divide both sides by 10

k = 77/10

see explanation

step-by-step explanation:

a

(6r + 7) + (13 + 7r) ( remove brackets and collect like terms )

= 6r + 7 + 13 + 7r

= 13r + 20

b

remove brackets and collect like terms

13 - r - 1 + r

= 12 - r

c

remove brackets and collect like terms

= - 8 - r + 2r - 4

= - 12 + r

d

remove brackets and collect like terms

= 7r - - - 6r

[-   - = - - = - ]

= r -