All Exams Test series for 1 year @ ₹349 only
Question

For the next three (03) items that follow :
Let A, B, C and D be mutually exclusive and exhaustive events and $\frac{P(A)}{2} = \frac{P(B)}{3} = \frac{P(C)}{5} = \frac{P(D)}{8}$.

What is \(\frac{[2P(A) + 3P(B)]}{[4P(C) + 5P(D)]}\) equal to ?

This question was previously asked in
NDA 2 2026 GAT Question Paper (13-Sep-2026)
The correct answer is
13/60

To solve the problem, we are given that the events \(A\), \(B\), \(C\), and \(D\) are mutually exclusive and exhaustive. Furthermore, it is given that:

\(\frac{P(A)}{2} = \frac{P(B)}{3} = \frac{P(C)}{5} = \frac{P(D)}{8} = k\)

Here, \(k\) is a constant. From this equation, we can express the probabilities of each event as:

  • \(P(A) = 2k\)
  • \(P(B) = 3k\)
  • \(P(C) = 5k\)
  • \(P(D) = 8k\)

Since the events are exhaustive, their probabilities sum to 1:

\(P(A) + P(B) + P(C) + P(D) = 1\)

Substituting the expressions for the probabilities, we have:

\(2k + 3k + 5k + 8k = 1\)

Simplifying this gives:

\(18k = 1\)

Therefore, \(k = \frac{1}{18}\).

Next, we need to find the value of:

\(\frac{[2P(A) + 3P(B)]}{[4P(C) + 5P(D)]}\)

Substituting the values of the probabilities:

\(\text{Numerator} = 2(2k) + 3(3k) = 4k + 9k = 13k\)

\(\text{Denominator} = 4(5k) + 5(8k) = 20k + 40k = 60k\)

Thus, the expression simplifies to:

\(\frac{13k}{60k} = \frac{13}{60}\)

The correct answer is therefore \(\frac{13}{60}\).

Was this answer helpful?

Similar Questions

  1. An edible oil is sold at the rates 150, 200, 250, 300 rupees per litre in four consecutive years. Assuming that an equal amount of money is spent on oil by a family in every year during these years, what is the average price of oil in rupees (approximately) per litre ?
  2. Let \(m = 77^n\). The index \(n\) is given a positive integral value at random. What is the probability that the value of \(m\) will have 1 in the units place ?
  3. What is \(P(A) + P(B) + P(C)\) equal to ?
  4. A, B, C are three mutually exclusive and exhaustive events associated with a random experiment. If \(3P(B) = 4P(A)\) and \(3P(C) = 2P(B)\), then what is \(P(A)\) equal to?
  5. A die has two faces with number 4, three faces with number 5 and one face with number 6. If the die is rolled once, then what is the probability of getting 4 or 5?
  6. A box contains 2 black, 4 yellow and 6 white balls. Three balls are drawn in succession with replacement. What is the probability that all three are of the same colour?
  7. The letters of the word ZOOLOGY are arranged in all possible ways. What is the probability that the consonants and vowels occur alternatively?
  8. A natural number \(x\) is chosen at random from the first 100 natural numbers. What is the probability that \(x^2 + x > 50\)?
  9. A fair coin is tossed till two heads occur in succession. What is the probability that the number of tosses required is less than 6?
  10. Two perfect dice are thrown. What is the probability that the sum of the numbers on the faces is neither 9 nor 10?

Important Questions from Probability

  1. The probability of being 53 Sundays in year 2020 is-

  2. Three dice are thrown randomly. The probability of coming 3 in at least one die is

  3. The probability of having 53 Tuesdays in an ordinary year is:

  4. Two dice are thrown simultaneously The probability of getting the sum 2 or 8 or 12 is

  5. If two balanced dice are tossed once, the probability of the event, that the sum of the integers coming on the upper sides of the two dice is 9, is

Need Expert Advice?
Test Series
NDA img
Defence
NDA 2026 Mock Test Series (Latest Pattern)
503 Tests 1 Tests Free
1148 Attempts
4.7(142)
English, Hindi

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App