Quantitative Aptitude - Arithmetic Ability Questions

Let B's present age = x years. Then, A's present age = (x + 9) years.
(x + 9) + 10 = 2(x - 10)

 => x + 19 = 2x - 20

 => x =39.

The word 'LEADING' has 7 different letters.

When the vowels EAI are always together, they can be supposed to form one letter.

Then, we have to arrange the letters LNDG (EAI).

Now, 5 (4 + 1) letters can be arranged in 5! = 120 ways.

The vowels (EAI) can be arranged among themselves in 3! = 6 ways.

Required number of ways = (120 x 6) = 720.

Weight of the teacher = (35.4 x 25 - 35 x 24) kg = 45 kg.

Let the two conditioners be A and B

'A' cools at 40min

'B' at 45min

Together = (a x b)/(a + b)

= (45 x 40)/(45 + 40)

= 45 x 40/85

= 21.1764

= 22 min (approx).

The terms are alternatively multiplied by 1.5 and divided by 3. However, 18.5 does not satisfy it.

At 3 O'clock, Minute hand is at 12 while the Hour hand is at 3. Again the minute hand has to sweep through ( 30 x 5 ) ie 150° for reaching the figure 5 to show 25 mins. 

Simultaneously the Hour hand will also rotate for 25 mins. Thus starting from the mark, 3 the hour hand will cover an angle = (25 x 30) / 60 = 12.5° 

Hence, Angle between Hour and the Minute hand = ( 60 - 12.5 ) = 47.5°

This sunday morning at 8:00 AM, the watch is 5 min. Slow, and the next sunday at 8:00PM it becomes 5 min 48 sec fast.  The watch gains 5+54860 min in a time of  (7×24)+12 = 180 hours. 

To show the correct time, it has to gain 5 min.

545min→180hours

5min ->

5542×180

8313hrs=72hrs+1113hrs=3days+11hrs+20min

So the correct time will be shown on wednesday at 7:20 PM

Commission up to 10000 = 10000x9100 = 900 

Again after 10000, 

              Commission    :   Bonus 

                           9       :   3 

                         3x        :   x

 Therefore,   Bonus = 1380-900×14 = Rs. 120