Quantitative Aptitude - Arithmetic Ability Questions

Average = (11 + 22 + 33 + 44 + 55 + 66 + 77 + 88 + 99) / 9

             =( (11 + 99) + (22 + 88) + (33 + 77) + (44 + 66) + 55) / 9

             = (4 * 110 + 55)/9 =  495 / 9 = 55. 

Given that 3x-y=27, 3x+y=243

⇒3x-y =33 , 3x+y=35

 => x-y=3, x+y=5

 => x = 4

Here Sample space S = { HH, HT, T1, T2, T3, T4, T5, T6 }

Let A be the event that the die shows a number greater than 4 and B be the event that the first throw of the coin results in a tail then,

 A = { T5, T6 }

 B = { T1, T2, T3, T4, T5, T6 }

Therefore, Required probability = PAB=PA∩BPB=2868=13

Given the price of a commodity is decreased by  p = 20%

And its consumption is increased by q = 10%

Now, required increase or decrease in the expenditure on the commodity can be 

p + q + pq/100 = -20 + 10 - 200/100 = -10 - 2 = -12%.

Hence, decrease in the expenditure = 12%

Except 437 all others are prime numbers.

By trial and error method, when we substitute 

x = 0

Both LHS and RHS are equal.

Given compound interest for 3 years = Rs. 1513.2

and simple interest for 5 years = Rs. 2400

Now, we know that  C.I = P1+R100n - 1

=> 1513.2 = P1+R1003 - 1 ...........(A)

And S.I = PTR/100

=> 2400 = P5R/100 ..................(B)

By solving (A) & (B), we get

R = 5%.

2nd Jan 1901 means
(1900 years and 2 day)
Now, 1600 years have 0 odd day
300 years have 1 odd day
2 days has 2 odd day
Total no. of odd days = 0 + 1 + 2 = 3 days
Hence, the day on 2nd Jan 1901 was Wednesday.