Quantitative Aptitude - Arithmetic Ability Questions

Let 'R%' be the rate of interest

From the given data,

$$\begin{gathered} 25202400 = 1 + R10041 + R1003 \\ ⇒1 + R100 = 6360 \\ ⇒R = 5 \end{gathered}$$

Hence, the rate of interest R = 5% per annum.

Any two digit number can be written as (10P + Q), where P is the digit in the tens place and Q is the digit in the units place.
P + Q = 8 ----- (1)
(10Q + P) - (10P + Q) = 54
9(Q - P) = 54
(Q - P) = 6 ----- (2)
Solve (1) and (2) P = 1 and Q = 7
The required number is = 17

We Know that sum of the n natural numbers =n(n+1)2

Then sum of 50 natural numbers= 50(51)2= 1250

Average of the 50 natural numbers = 125050 = 25.5

Given speed of the bike after servicing = 55 kmph

Time taken for travelling some distance at 55 kmph = 5 hrs

Then, 

Distance = Speed x Time = 55 x 5 = 275 kms.

Now, 

Speed of the bike before servicing = 35 kmph

Distance = 275 kms

Now, Time = Distance/Speed = 275/35 = 7.85 hrs =~ 8 hrs.

Total engineers = 4800

Number of female engineers = 3/8 x 4800 = 1800

Then, number of male engineers = 4800 - 1800 = 3000

Now, required is female engineers is what percentage of the number of male engineers

=> 1800 is what % of 3000

=> p x 3000/100 = 1800

=> 30p = 1800

p = 60%

Hence, female engineers is 60 percentage of the number of male engineers.

By simplifying, we get 4/3

P(heart cards)=13/52

P(diamond cards)=13/52

P(heart or diamond)=13/52+13/52=1/2