Quantitative Aptitude - Arithmetic Ability Questions

Total numbers in die=6

P(multiple of 2)=1/2

P(multiple of 5)=1/6

P(multiple of 2 or 5)=2/3

If a number ends with 5, 0 then the number will be divisible by 5
Here only 5 is present, end place will be fixed by 5 so, 

Let A’s investment be= 7a
Let B’s investment be= 6a
Let C’s investment be= 5a
Their investment in 2ndyear:= (125% of 7a): (120% of 6a) : (115% of 5a) = 175 : 144 : 115

With slight modifications, the basic formula can be made to deal with compounding at intervals other than annually.

Since the compounding is done at six-monthly intervals, 4 per cent (half of 8 per cent) will be added to the value on each occasion.

Hence we use r = 0.04. Further, there will be ten additions of interest during the five years, and so n = 10. The formula now gives:

V = P(1 + r)10 = 5,000 x (1.04)10 = 7,401.22

Thus the value in this instance will be £7,401.22.

In a case such as this, the 8 per cent is called a nominal annual

rate, and we are actually referring to 4 per cent per six months.

Given that three athletes can complete one round around a circular field in 16, 24 and 36 min respectively.

Now, required time after which they met for the first time = LCM of (16, 24 & 36) min

Now, LCM of 16, 24, 36 = 144 minutes = 2 hrs 24 min.

$$\begin{gathered} Given 3.2% of 500 × 2. 4% of ? = 312 \\ Then, \\ 3.2 x 500100 x 2.4 x ?100 = 312 \\ 16 x 2.4x?100 = 312 \\ 9.6 x ?25 = 312 \\ 9.6 x ? = 7800 \\ ? = 78009.6 \\ ? = 812.5 \end{gathered}$$