Question Details

Directions (55-57): Read the following table carefully and answer the questions given below.

In the table some numbers are given and the probability of picking that number is given.

NUMBERS Probability
Q
16
2.5
13
Q − 2.5
13
P
16
4Q5 2
16
18.75
16

If R = 5Q – 20, then find the value of R.

Options

A

3

B

8

C

4

D

5

Show Answer

Correct Answer :

Option D

5

5

Solution :

The correct answer is 5.

To find the value of R, we first need to determine the value of the variable Q from the table. Let us analyze the sequence formed by the values listed in the "NUMBERS" column of the table:

1st term: Q
2nd term: 2.5
3rd term: Q-2.5
4th term: P
5th term: 4Q-52
6th term: 18.75

By observing the relationship between the terms, we can see that they form a multiplication series where each term is obtained by multiplying the preceding term by a factor that increases by 0.5 at each step:
Term(n)=Term(n-1)×[0.5+(n-2)×0.5]

Specifically:
• 2nd term = 1st term ×0.52.5=Q×0.5
• Solving for Q:
Q=2.50.5=5

Let us verify the value Q=5 by checking the remaining terms in the sequence:
• 1st term = 5
• 2nd term = 5×0.5=2.5
• 3rd term = Q-2.5=5-2.5=2.5 (which is 2.5×1.0=2.5)
• 4th term (P) = 2.5×1.5=3.75
• 5th term = 4(5)-52=152=7.5 (which matches 3.75×2.0=7.5)
• 6th term = 7.5×2.5=18.75 (which matches the table value of 18.75)

The sequence is consistent, validating that Q=5.

Now, we substitute Q=5 into the equation for R:
R=5Q-20
R=5(5)-20
R=25-20
R=5

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