CAT Questions

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After 5 mins ..... 3 persons will get rumour
After 10 mins .... 3x2 + 3 = 9 = 32 persons will get
after 15 =5x3 min ......9x2 + 9 =27 = 33 persons will get news.
.
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after 5x6 mins ... 36 = 729 persons will get news.

Therefore, time taken to spread the rumour to 729 persons is 30 minutes.

Let the Present age of arun is x
Gokul's age = 5-2 = 3
x-6/18 = 3
x-6 = 54
x = 60
Arun's present age = 60 years

As minute hand covers, 60 degrees

Minute hand covers 4800/60 = 80°

Ratio of times taken by P & Q = 100 : 130 = 10:13

Let Q takes x days to do the work

Then, 10:13 :: 23:x

=> x = 23x13/10

=> x = 299/10

P's 1 day's work = 1/23

Q's 1 day's work = 10/299

(P+Q)'s 1 day's work = (1/23 + 10/299) = 23/299 = 1/13

Hence, P & Q together can complete the work in 13 days.

Clealry, C and D sit opposite to each other. So, if A sits opposite to cook, B shall be the cook.
Now, B is to the right of barber. So, one of the rest, say C will be barber.
Clealry, then D on the opposite side shall be washerman or tailor. But, washerman is left of tailor and D on the left of A.
So, D is washerman and A is tailor.

Thus, A and B are Tailor and Cook.

There are total 9 places out of which 4 are even and rest 5 places are odd.

4 women can be arranged at 4 even places in 4! ways.

and 5 men can be placed in remaining 5 places in 5! ways.

Hence, the required number of permutations  = 4! x 5! = 24 x 120 = 2880

The minute hand angle is the easiest since an hour (i.e. 60 minutes) corresponds to the entire 360 degrees, each minute must correspond to 6 degrees. So just multiply the number of minutes in the time by 6 to get the number of degrees for the minute hand.
Here 15 minutes corresponds to 15 x 6 = 90 degrees

Next, you have to figure out the angle of the hour hand. Since there are 12 hours in the entire 360 degrees, each hour corresponds to 30 degrees. But unless the time is EXACTLY something o'clock, you have to write the time as a fractional number of hours rather than as hours and minutes.
Here the time is 9:15 which is (9 + 15/60) = 37/4 hours. Since each hour corresponds to 30 degrees, we multiply 30 to get (37/4)(30) = 277.5 degrees.

Since the hour hand is at 277.5 degrees and the minute hand is at 90 degrees, we can subtract to get the angle of separation. 277.5 - 90 = 187.5 =~ 360 - 187.5 = 172.5 degrees.