Data Sufficiency 2
Practice and master this topic with our carefully crafted questions.
Each of the questions given below consists of a question followed by three statements. You have to study the question and the statements and decide which of the statement(s) is/are necessary to answer the question.
The mean temperature of Monday to Wednesday was 370 C and of Tuesday to Thursday was 340 C. what was the temperature on Thursday ?
I. The temperature on Thursday was 4/5th that of Monday.
II. The mean temperature of Monday and Thursday was 40.50 C .
III. The difference between the temperature on Monday and that on Thursday was 90 C.
M + T + W = (37 x 3)
M + T + W = 111 -------------- (i)
T + W + Th = (34 x 3)
T + W + Th = 102 ------------- (ii)
I gives, Th = 4/5 M M = 5/4 Th
Using it in (i), we get :
5/4 Th + T + W = 111 .............. (iii)
On subtracting (ii) from (iii),
we get : 1/4 Th = 9 Th = 36
Thus, I alone gives the answer.
II gives, M + Th = (40.5 x 2) M + Th = 81 .--------(iv)
On subtracting (ii) from (i), we get M - Th = 9 ----- (v)
From (iv) and (v), we get Th = 36.
Thus, II alone gives the answer.
III gives, M - Th = 9.
Clearly, III with given results, does not give the answer.
Correct answer is (C).
How many marks did Priya secure in English ?
I. The average marks obtained by Priya in four subjects including English is 60.
II. The total marks obtained by her in English and Mathematics together is 170.
III. The total marks obtained by her in Mathematics and Science together is 180.
I gives, total marks in 4 subjects = (60 x 4) = 240.
II gives, E + M = 170
III gives, M + S = 180.
Thus, none of (A), (B), (C), (D) is true.
Correct answer is (E).
In a cricket eleven, the average age of eleven players is 28 years. What is the age of the captain ?
I. The captain is eleven years older than the youngest player.
II. The average age of 10 players, other than the captain is 27.3 years.
III. Leaving aside the captain and the youngest player, the average ages of three groups of three players each are 25 years, 28 years and 30 years respectively.
Total age of 11 players = (28 x 11) years = 308 years.
I. C = Y + 11 C - Y = 11 .... (i)
II. Total age of 10 players (excluding captain)
= (27.3 x 10) years = 273 years.
Age of captain = (308 - 273) years = 35 years.
Thus, C = 35. .... (ii)
From (i) and (ii), we get Y = 24
III. Total age of 9 players
= [ (25 x 3) + (28 x 3) + (30 x 3)] years
= 249 years.
C + Y = (308 - 249) = 59 .... (iii)
From (i) and (iii), we get C = 35.
Thus, II alone gives the answer.
Also, I and III together give the answer.
Correct answer is (C).