Quantitative Aptitude - Arithmetic Ability Questions

4b=6c⇒b=32c and 3a=4b⇒a=43b=43(32c)=2c 

a+b+c=2729 ⇒2c+32c+c=2729 ⇒c=629

 ∴a2+b2+c2=(a+b+b)2-2(ab+bc+ca) 

=(2729)2-22c×32c+32c×c+c×2c 

 =729×29-2×132 c2

= 87

Let t be the usual time. If the usual rate is 1 unit, then the unusual rate is 6/7.
Balance by the distance,
1 x t = (6/7)(t + 30)
7t = 6(t + 30)
we get t as,
t = 180 minutes = 3 hrs.

Ratio of length and breadth is 6 : 5
∴ Length = 6x
Breadth = 5x
∴ Area = l x b = 30x2
∴ Perimeter = 2 (l + b) = 2(6x + 5x) =22x
∴ (30*x*x)/(22x)= 60/11
∴ X = 4
∴ Length = 6x = 6 x 4 = 24 units

Since two of the eight first class petty officers are to fill two different offices, we write 8P2=56

Then, two of the six second class petty officers are to fill two different offices; thus, we write 6P2 =30

The principle of choice holds in this case; therefore, the members have 56 x 30 = 1680 ways to select the required office holders

Let the speed of the train be 'S' kmph

From the given data,

Distance = Length of train = D = 200 mts = 200 x 18/5 kms

Time = 10 sec

given speed of the motorcycler = 12 kmph

Relative speed as they are moving in the same direction = (S - 12) kmph

$$\begin{gathered} (S- 12) = 200 x 18515 \\ S - 12 = 48 \\ S = 60 kmph \\ \end{gathered}$$

Hence, the speed of the train = S = 60 kmph

Now,

Let the speed of the jeep be 'x' kmph

$$\begin{gathered} 60 - x = 200 x 18520 \\ 60 - x = 36 \\ x = 60 - 36 \\ x = 24 kmph \end{gathered}$$

Therefore, the speed of the jeep = x = 24 kmph.

Methods for selecting 4 questions out of 5 in the first section = 5 x 4 x 3 x 2 x 1/4 x 3 x 2 x 1 = 5. Similarly for other 2 sections also i.e 5 and 5

So total methods = 5 x 5 x 5 = 125.

If he wants to give these books equally to 2 of his friends, then 1 book will remain, it means possible number of books = 15,17,19,21,23,25,27,29
If he wants to give these books equally to 3 of his friends, then 2 books will remain, it means possible number of books = 17,20,23,26,29
If he wants to give these books equally to 4 of his friends, then 3 book will remain, it means possible number of books = 15,19,23,27
common number is only 23 so it will be answer

15! - 14! - 13!

= (15 × 14 × 13!) - (14 × 13!) - (13!)

= 13! (15 × 14 - 14 - 1)

= 13! (15 × 14 - 15)

= 13! x 15 (14 - 1)

= 15 × 13 × 13!