Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
English and Logical Reasoning Prep GuideLogical ReasoningArithmetic Reasoning

A man wears socks of two colours - black and brown. He has altogether 20 brown socks in a drawer. Supposing he has to take out the socks in the dark, how many must he take out to be sure that he has a matching pair.

Options

  1. A3
  2. B39
  3. C5
  4. DNone of these

Correct answer

A. 3

Step-by-step solution

It is given that he has socks of 2 colours only. It is obvious that if he only takes out one sock then he can’t have a matching pair (since by definition a pair is 2 socks). If he takes out 2 socks, he could select 2 that are the same colour, but he could also select one of each colour — which is not a matching pair. Therefore, 2 socks are not enough to guarantee that he will have a matching pair If he takes out 3 socks then there are 2 scenarios — the first being that the first two socks he selec

Practice Arithmetic Reasoning on Quantrex Academy →

More from Arithmetic Reasoning

A straight line is 36   cm long. Points are to be marked on the line from both the ends so that the first point is at a distance of 1   cm from one end, the second point Directions - The following pie chart shows the expenditure (in percentage) of five companies P, Q. R. S and T in the year 2016. Total Expenditure = R s .   48 crores What was The sum of present ages of 3 persons is 72 yrs. Seven years ago, their ages were in the ratio (4: 6: 7 ). What are their present ages in years?There are some cows, bulls, and 45 hens in a group. One caretaker looks after 15 animals. The number of bulls is twice the number of cows. If the number of the head is less than thA is half as old as B .   C is twice as old as B . How many times is C as old as A ?A is 4 times as heavy as B. B is half the weight of C. C is 2 . 5 times as heavy as D. D is one fourth the weight of E. Who is the heaviest?The average of nine numbers is 60, that of the first five numbers is 55 and the next three is 65. The ninth number is 10 less than the tenth number. Then, tenth number is -Estimates based on cluster samples are usually more reliable: Full Arithmetic Reasoning list All English and Logical Reasoning Prep Guide PYQs