Question

In the table given below, what is the number of green marbles in jar R?
Number of solid coloured marbles in three jars:

Jar	Number of red marbles	Number of green marbles	Total number of red and green marbles
P	$ x $	$ y $	$ 80 $
Q	$ y $	$ z $	$ 120 $
R	$ z $	$ z $	$ 160 $

A. $ 70 $
B. $ 80 $
C. $ 90 $
D. $ 100 $
E. $ 110 $

Answer 1

Hint: In this question we have to find the number of marbles in jar R. We can see from the above table that the total number of red marbles in jar R is $ z $ and the total number of green marbles in jar R is $ z $ and the whole total or we can say that the sum total of these are $ 160 $ . So we have to find the value of $ z $ i.e. green marbles. We will create an equation from these variables. And We can solve the given problem by applying the equation.

Complete step-by-step answer:
We need to first understand the requirement of the question which is that we have to find the value of green marbles i.e. $ z $ .
We can create the equation with the total number of marbles in each jar.
We have the equations :
  $ x + y = 80,y + z = 120,z + z = 160 $ .
We will take the third equation as we have to find the number of marbles of third jar i.e. jar R and solve it,
By adding we can write
  $ 2z = 160 $ .
So it gives us :
 $ z = \dfrac{{160}}{2} = 80 $ .
It gives us that red marbles in jar R is $ 80 $ and the green marbles in jar R is $ 80 $ .
Hence the correct option is (b) $ 80 $ .
So, the correct answer is “Option b”.

Note: We should always be careful what the question is asking. Based on the requirement and by observing all the necessary information that is already available in the question we gather the information and then create an equation or by unitary method whichever is applicable, then we solve the problem and then verify the answer by putting the value in the problem and see whether we get the same answer or not.