A, B and C can cmplete a job in 6 days, 1 days and b days respectively. They started it and worked for 2 days, then A left. B left after another day. C complete the remaining part of the job in another day. Who completed the maximum part of the job. I. a>9 II. b>12
A :
If the question can be answered by using statement I alone but not by using II alone.
B :
If the question can be answered by using statement II alone but not by using I alone.
C :
If the question can be answered by using either statement alone.
D :
If the question can be answered by using both the statements together but not by either statement alone.
Answer: C Part of job done by A = 1/3. B worked for 3 days and C worked for 4 days. Statement I : part of job done by B = 3/a < 1/3 C must have done more than 1/3rd of it. C completed the maximum part of it. Thus, statement I is sufficient. Statement II :: part of job done by C = 4/b < 1/3 B must have done > 1/3rd of it. B completed the maximum part of it. Hence, statement II is also sufficient.
Q. No. 182:
Pipes A,B and C can be used for filling or emptying with the same capacity. If A and B are used for filling and C is used for emptying, a tank would be filled in 6 hours. Find the time taken by C to fill it. I. If all the pipes are used for filling, the tank would be filled in 2 hours. II. If B and C are used for filling and A is used for emptying, the tank would be filled in 6hr.
A :
If the question can be answered by using statement I alone but not by using II alone.
B :
If the question can be answered by using statement II alone but not by using I alone.
C :
If the question can be answered by using either statement alone.
D :
If the question can be answered by using both the statements together but not by either statement alone.
Answer: A Let the time taken by A,B and C to fill the tank be a, b and c minutes respectively. 1/a + 1/b - 1/c = 1/6 ...........(i) Statement I : 1/a + 1/b + 1/c = 1/2 ..............(ii) From i and ii :- 2/c = 1/2 - 1/6 = 1/3 => c = 6 Hence, I alone is sufficient. Statement II : 1/b + 1/c - 1/a = 1/6 ...........(iii) From i and iii : a = c a is unknown , c cannot be found. Required time cannot be found. Hence, B is not sufficient.
Q. No. 183:
Ravi rowed a boat from a point P in a river 24km downstream and then returned to P. Find the speed of his boat in still water if his upstream journey took x hours. I. The time he took for the downstream journey was 3 hours less than that for the upstream journey and x =6. II. His upstream and downstream speeds were 4kmhr and 6kmph respectively.
A :
If the question can be answered by using one of the statement alone, but cannot be answered by using the other statement alone.
B :
If the question can be answered by using either statements.
C :
If the question can be answered by using both statements together, but cannot be answered by using either statements alone.
D :
If the question cannot be answered even by using both the statements together.
A, B and C ran a race with distinct speeds. Who won the race ? I. The average of the speeds of A and C when doubled would be equal the sum of the average of the speeds of A and B and the average of the speeds of B and C. II. Twice the speed of A was equal to the thrice the speed of C.
A :
If the question can be answered by using one of the statement alone, but cannot be answered by using the other statement alone.
B :
If the question can be answered by using either statements.
C :
If the question can be answered by using both statements together, but cannot be answered by using either statements alone.
D :
If the question cannot be answered even by using both the statements together.
Answer: C Let the speed be a, b and c km/hr. Statement I : 2((a+c)/2) = (a+b)/2 + (b+c)/2 => a+c/2 = b Hence, b is the average speed of r and t ............(i) Statement II : 2a = 3c a/c = 3/2. => a > c From both the statement : A won the race.. Both statements are required to answer the question.
Q. No. 185:
Trains P, Q and R have their speeds in the ratio 1:2:3. Find the longest train among them. I. Time taken by P t cross its own length is equal to the sum of four times the time taken by Q to cross its own length and thrice the time taken by R to cross its own length. II. The train which takes the maximum time to cross its own length is P.
A :
If the question can be answered by using one of the statement alone, but cannot be answered by using the other statement alone.
B :
If the question can be answered by using either statements.
C :
If the question can be answered by using both statements together, but cannot be answered by using either statements alone.
D :
If the question cannot be answered even by using both the statements together.
Answer: A Let the speed of P be x m/sec, speed of Q = 2x m/sec and speed of R = 3x m/sec. Let the length of P, Q and R be am, bm and cm respectively. Statement I : a/x = 4(b/2x) + 3(c/3x) => a = 2b+c => a > 2b, a > c. P is the longest train. Statement II : a/x > b/2x >c/3x => a> b/2 > c/3 We cannot answer the question, II is not sufficient.
Q. No. 186:
Between A and B, one always truth (truth teller) and the other always lies (liar). Who is the truth teller ? I. A said "We both are liars". II. B said "We both are truth tellers".
A :
If the question can be answered by using statement I alone but not by using statement II alone.
B :
If the question can be answered by using statement II alone but not by using statement I alone.
C :
If the question can be answered by using either of the statements alone.
D :
If the question can be answered by using both the statements together but not by either of the statements alone.
Answer: C Statement I : A can't be truth teller, as there is only one liar. => A is liar, B is truth teller. Statement I alone is sufficient. Statement II : B can't be truth teller as there is only one truth teller. B is a liar. A is a truth teller. Statement II alone is sufficient.