Quantitative Aptitude - Arithmetic Ability Questions

We know the formula for calculating

The compound interest C = P1 + r100n - 1 where P = amount, r = rate of interest, n = time

Here P = 5000, r1 = 10, r2 = 20

Then $$\begin{gathered} C = 65001 + 101002 x 1 + 201002 - 1 \\ = 6500 x 18562500 \\ = 65 x 185625 \end{gathered}$$

C = Rs. 4826.

 C.I. when interest compounded yearly

Rs.5000*1+4100*1+12*4100

 Rs.5000*2625*5150

=Rs.5034

C.I. when interest iscompounded half-yearly 

 Rs.5000*1+21003

= Rs. 5306.04

Difference = Rs. (5306.04 - 5304) = Rs. 2.04

S.I=PNR/100

P1+20100n > 2P 

Now, (6/5 x 6/5 x 6/5 x 6/5) > 2.

So, n = 4 years.

The probability of an impossible event is 0.

The event is known ahead of time to be not possible, therefore by definition in mathematics, the probability is defined to be 0 which means it can never happen.

The probability of a certain event is 1.

Let the principle amount be Rs. P

Interest rate = 12%

Total amount he paid after 5 years = Rs. 1280

ATQ, 

$$\begin{gathered} P + I = PTR100 + P \\ 1280 = PTR100 + 1 \\ 1280 = P5 x 12100 + 1 \\ 16P10 = 1280 \\ P = 80 x 10 = 800 \end{gathered}$$

Hence, the amount he borrowed = P = Rs. 800.

Investments ratio is = 3:1
Time period ratio is = 2:1

As they are proportional to gain

------
Gain ratio of Vishal and raghu = 6:1

But given Raghu got Rs. 4000, 

=? 1 ----- 4000
     7 -----    ?

=> Rs.28,000

The total gain = Rs.28,000