Question

A jar contains blue and green marbles the number of green marble is 5 more than twice the number of blue .If the probability of drawing a blue marble one at random is 2/7 how many green marbles are there in jar

Answer 1

Let the blue marbles be x . 

Then green marbles are 2x + 5 

Total no. of marbles = 3x+5 

so , x/3x+5 =2/7 

By cross-multiplication , 

we get , 7x = 6x+10 

i.e. x =10 (blue marbles )

Hence , blue marbles =10 

             green marbles = 2(10) +5 = 20 +5 = 25

Answer 2

Answer:

Step-by-step explanation:

Let the number of blue marbles be x .  

Then the number of green marbles= 2x + 5  

Total no. of marbles = 3x+5  

∴ $\frac{x}{3x+5}$ = $\frac{2}{7}$

By cross-multiplication, we get,

7x = 6x+10  

∴ x =10

∴ The number of :

blue marbles =10  

and,  green marbles = 2(10) +5 = 20 +5 = 25