Data Sufficiency Questions, Tips and Method

Data sufficiency is an important part of quantitative aptitude section of every competitive exam including IBPS, LIC, Civil services, CAT and GMAT. In almost every exam there are several questions from data sufficiency.

Most of the candidates try to solve data sufficiency questions by guess work. As every question carries same marks, questions in this part also deserve some time. Instead of guess work use a simple strategy  as give below and avoid guessing the answer.


Steps in solving Data Sufficiency questions 

1) Read the given problem. Don't assume anything except universal facts.
2) Take the first statement and combine it with main statement. Try to find the answer.
3) If you are unable to find the answer using 2nd step then combine second statement and combine it with main statement and try to find answer.
4) If you are unable to find an answer using second statement then add both statements with main statement and try to find answer
5) If even now you can't find answer, simply tick both statements are insufficient.

Directions :-
Marks A as answer if statement I alone is sufficient to answer the question
Marks B as answer if statement II alone is sufficient to answer the question
Marks C as answer if statement I and II together are sufficient to answer the question but neither statement aloneis sufficient to answer the question

Data Sufficiency questions and answers


Question 1. How many people are there in the plain ?
Statement I : 25% passengers are women and 35% are children.
Statement II : There are 24 men in the plain
Answer
From Statement I we can conclude that there are 40% men in the plain but we can't find the exact number of passengers
From Statement two  : Number of men passengers = 24
By combining both the statements we get, total number of passengers = 24 * 100/40 = ( you don’t need to calculate the answer )
Hence answer is C


Question 2. What is the difference between monthly income of Ram and Chaaru
Statement I : Ram earns Rs 6000 less than Shaam
Statement II : Chaaru earns Rs 6000 more than Shaam.
Answer : In this question we don't need to in depth. Simply there is difference of Rs 12000 


Question 3. Is x divisible by 28 ?
Statement I : x is divisible by 20
Statement II : x is divisible by 84
Answer. Using statement I - x is divisible by 4 and 5
Using statement II - x is divisible by 3,4, and 7.
By using both statements we can conclude that x is divisible by 28 ( 4*7), hence answer is C.

Question 4. P,Q,R,S and T are five friends. Their mean age is 18. What is the age of R ?
Statement I : P's age is 18
Statement II : Q's age is 2 years less than T and T's age is 6 years less than S.
Statement III : R's age is 6 years more than B's age and 4 years more than T's age.
Answer : P+Q+R+S+T = 90
From Statement I : Q+R+S+T = 72
From Statement II : Q = T - 2 and T=S - 6
So S = T + 6
Statement III : R = Q+6 and R = T + 4
Age of every friend can be defined in terms of T's age by using all three statements. So  we can reach the answer using all three statements. Hence answer is C.


Tips to solve Data Sufficiency questions

  • Never try to reach final answer as it is not asked. You need to find whether the information provided is enough to solve the given problem or not. 
  • Never make any assumption. Use only universal rules { eg. a + b = a + b - (a U b) } 
  • Try to solve questions by using above strategies  
  • Solve question step by step. First try to find answer using first statement then second and finally with both. Then mark the answer 
  • Even if you find answer with only one statement, then try to find answer with remaining statement as sometimes there is an option that answer can be find with both statements separately.
  • Move on quickly and mark answer can't be found in case you are unable to reach any conclusion with information provided.


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