CSAT DAILY MISSION #99

May 15, 2015

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Question 1

Ram had some money. He gave one quarter if this money to Vinod and one third of the remaining to Rishabh. If the money remaining with him is Rs. 40, what was the initial money he had?
(A) 60
(B) 80
(C) 90
(D) 120

Question 2

A batsman in his 17th innings makes a score of 85, and thereby increases his average by 3. What is his average after 17 innings?
(A) 36
(B) 37
(C) 38
(D) 39

Question 3

A ship develops a leak 12 km from the shore. Despite the leak, the ship is able to move towards the shore at a speed of 8 km/hr. However the ship can stay afloat only for 20 minutes. If a rescue vessel were to leave from the shore towards the ship, and it takes 4 mins to evacuate the crew and passengers of the ship, what should be the minimum speed of the rescue vessel in order to be able to successfully rescue the people aboard the ship?(A) 37 km/hr
(B) 28 km/hr
(C) 41 km/hr
(D) 25 km/hr

Question 4

A single thread made up of carbon nanotube is designed in a manner that it is wound around the entire earth and just fits it. It touches the earth at all points. Due to rising temperature, the thread heats up and expands by 10 metres in length. The thread is still spherically shaped and rises above the earth’s surface equally at all points. What would be the gap between the earth’s surface and thread? Assume the earth to be perfect sphere with radius of 6400 km.(A) 1.6cm
(B) 16 cm
(C) 1.6 m
(D) 16 m

Question 5

One-third of a certain journey is covered at the rate of 25 km/hr, one-fourth at the rate of 30 km/hr, and the rest at 50 km/her. Find the average speed for the whole journey.(A) 33
(B) 35
(C) 37
(D) 40

N.B. Please note that the official timings for publication of these questions is 11 am daily.

SOLUTIONS TO DAILY CSAT MISSION #100

1. (B) 2. (B) 3. (D) 4. (B) 5. (D)

Explanations
1. 10 years ago, total age of all family members: 24×4 = 96.
Today, total age of all family members: 24×6 = 144 (because the average today is same as 10 years ago).
Extra years added in these 10 years are 48. Each of the original four members have contributed 10×4 = 40 years.
So the two new children have contributed a total of 8 years. Therefore, their ages are 5 years and 3 years.

2. Simple enough problem. The paths can only start either from points A or C. Examples are AECDABC, CBAECDA, ABCEADC, ABCDAEC etc. A total of 12 such paths are possible.

3. This is a trick question. Ideally, you should answer this without solving anything. Here is how. If the first guy (Ram) has taken a third of the original number of mints provided (before returning four), then the original number of mints in the bowl would have to be divisible by 3. Since none of the first three options are divisible by 3, the answer is ‘none of these’.
The actual answer is 36, by the way.

4. In these kinds of questions, find out the LCM of all the times mentioned (4 hours, 6 hours and 3 hours in this particular question) and assume that the cistern has a total capacity of that much. LCM here is 12. So lets assume cistern’s capacity to be 12 litres.
Since pipe A alone fills it in 4 hours, so pipe A fills in 3 litres in one hour.
Since pipe B alone fills it in 6 hours, so pipe B fills in 2 litres in one hour.
Since pipe A alone empties it in 3 hours, so pipe C drains 4 litres in one hour.
Now, at the start, there are 6 litres in the cistern. C alone is opened for one hour after which the amount remaining would be 2 litres. Then B and C would be opened together for half an hour, which means combined, the cistern would be emptied at 2 litres an hour. After half an hour, the amount remaining would be 1 litre. From hereon, A, B and C would all be working together, and this means that overall, the cistern would get filled at 1 litre per hour. So to go from 1 litre to full capacity of 12 litres, it would take another 11 hours.
Total time taken: 1 hour + 0.5 hours + 11 hours = 12.5 hours.

5. Assume that the point where all the trains meet is P. Let the time taken for train A to get to P be ‘t’ hours. So, time taken by train B to get to P will be ‘t-3’ hours, because B has started after three hours. Now, distance covered by train A = speed x time i.e. 60t. And distance covered by train B = speed x time i.e. 90(t-3). Since distance of P from Mumbai always stays the same, 90(t-3) = 60t from which we get ‘t’ to be 9 hours.
So distance of P from Mumbai is 60t i.e. 60×9 = 540 km. Therefore, distance of P from Delhi is 1260-540 = 720 km.
In 6 hours, train C has travelled 720 km. So, speed of train C is 120 kmph.

Comments

43 responses to “CSAT DAILY MISSION #99”

Magesh N

July 20, 2015

Can u explain the q.4 for mission 100
Magesh N

July 20, 2015

can you explain -Q4 for mission 100
M2K

May 16, 2015

And is
1. B
2. B
3. A
4. B
5. A
Praful

May 16, 2015

1. b
2. b
3. a
4. c
5. a
dorjay

May 16, 2015

Thank you so much for starting this topic. I am not good at maths and now I hope to overcome it by practicing these questions regularly.
Rajnish

May 15, 2015

1-B
2-B
3-A
4-C
5-D
Etat

May 15, 2015

1. B – Rs. 80/-
2. B – 37
3. A – >= 30km/hr
4. C – 10/(2*pi) metres
5. A – 33.3* kph
NIKHIL

May 15, 2015

1) B
2) B
3) A
4) C
5) A
Rohan Pillai

May 15, 2015

1.B
2.B
3.A
4.C
5.A
Abhinandan Rout

May 15, 2015

For Mr. Palash : P is the point where A and B are meeting. It is where B overtakes A. So, if A has taken ‘t’ hours to get to P, then B would have taken ‘t-3’ hours to reach P. After that point P, B will move ahead of A and arrive earlier in Delhi.
Abhinandan Rout

May 15, 2015

For Mr. s : The first two trains have both started from Mumbai and met at a place called P (like Ahmedabad). So, the distance travelled by both is the same i.e. the distance from Mumbai to Ahmedabad. Since the second train has started 3 hours later at 9 pm, so its time taken is ‘t-3’ hours if ‘t’ is the number of hours taken by the first train. Speeds are given. Distance is same, therefore speed x time of the first = speed x time of the second.
masood

May 15, 2015

B B A – A
s

May 15, 2015

for yesterday ques 5?
s

May 15, 2015

can answer 5 be explained again..?
Narottam Kumar

May 15, 2015

1.B
2.B
3.C
4.?
5.C
abhi

May 15, 2015

Total time available to vessel to reach the ship=20-4=16 min
In 16 min with the relative speed i.e speed of ship+vessel it should cover a distance of 12km
So
In simple way,
Speed of ship(8)+speed of vessel(v)=12*60/16
60 is used bcoz time is in min. Not in hour
Nikhil

May 15, 2015

1-c
2-b
5-a
CHANDRAKANT

May 15, 2015

#99
ans: 1) B
2)B
3)B
4)C
5)A
ABHISHEK

May 15, 2015

1.B
2 B
3 A
4.
5 A
Ashwin

May 15, 2015

Q)3 = A , finally solved it.
Vikram

May 15, 2015

1. B
2. D
3. A
4. C
5. A
JVS

May 15, 2015

1. B
2. B
3. A
4. C
5. A
chand

May 15, 2015

1.B 2.B 3.A 5.A
Ashwin

May 15, 2015

can anyone explain Q)3 plzzz…
nidhi

May 15, 2015

1.B
2.B
3.A
5.A
sankirtan shukla

May 15, 2015

1. B
2. B
3. A
4. C
5. A
Rishabh

May 15, 2015

80…37…37kph…*….33kph are the answers
Vineet

May 15, 2015

BBAAA time taken 9 min 12 sec
Animesh

May 15, 2015

B
B
A
–
A
teedee

May 15, 2015

1.B
2.A
5.B
venky

May 15, 2015

Sorry I meant Option C is correct i.e 1.6 me
venky

May 15, 2015

4. D

Sol:

2pi*r = height of cylinder

h+10 = 2pi*(r+ increase in gap)

==> gap = 10/(2pi) metres

= 1.6 me
Amar

May 15, 2015

BBAAA
Anne

May 15, 2015

1. B
2. B
3. A
4. C
5. A
rajesh

May 15, 2015

B,B,C,A,A
raibahadur diljale

May 15, 2015

1. B: 80
2. B: 37
3. A: 37kmph
4. C: 1.6m
5. A: 33
venky

May 15, 2015

1.B
2.B
3.A
5.A
Ashwin

May 15, 2015

1.b
2.b
4.d
5.a
Jodhvir

May 15, 2015

1. B
2. B
3. A
4. A
5. B
sneha

May 15, 2015

1 D
2B
5 A
Palash Gupta

May 15, 2015

In yesterday’s 5th ques, how can you say that B will take t-3 time to reach point P as the speeds of A & B are different. Therefore it does not take t-3 time.
anu

May 15, 2015

1 b. 2 b. 3 a. 4. 5 a
Palash Gupta

May 15, 2015

1. D
2. B
5. A

Got 4 out of 5 questions correct yesterday. Thanks for the initiative