Quantitative Aptitude - Arithmetic Ability Questions

sum = [(S.I x T.D)/(S.I-T.D)] = Rs. [(375 x 250)/(375-250)] = Rs.750 

Rate = (100 x 375)/(750 x 3) =1623 %

$$\begin{gathered} log3437 \\ log737 \\ 13log77 \\ We know that logxx = 1 \\ => 13 \end{gathered}$$

Let the initial speed of Akhil be '4p' kmph

Then speed after decrease in speed = '3p' kmph

We know that, 

Change in speed == Change in time

According to the given data,

$$\begin{gathered} 243p - 244p = 35 - 2560 \\ => p = 12 \end{gathered}$$

Hence, the initial speed of Akhil = 4p = 4 x 12 = 48 kmph.

10% profit at half plot = 600000/2 x 10/100 = Rs. 30,000

15% profit at remaining half plot = 600000/2 x 15/100 = Rs. 45,000

Now, total profit = 30000 + 45000 = 75000

Profit % = 75000/600000 x 100 = 12.5 %

Let the age of the youngest child is 'X' years.
Then the child elder than the yongest is 'X + 3' yrs
Since each have 3yrs difference upto 5 children
And given that
=> X + X+3 + X+6 + X+9 + X+12 = 50
=> 5X + 30 = 50
=> X = 4 yrs.

Given total students in the class = 60
Students who are taking Economics = 24 and
Students who are taking Calculus = 32
Students who are taking both subjects = 60-(24 + 32) = 60 - 56 = 4
Students who are taking calculus only = 32 - 4 = 28
probability that a randomly chosen student from this group is taking only the Calculus class = 28/60 = 7/15.