Quantitative Aptitude - Arithmetic Ability Questions

Clearly, n(S) = (6 x 6) = 36.

Let E = Event that the sum is a prime number.

Then E= { (1, 1), (1, 2), (1, 4), (1, 6), (2, 1), (2, 3), (2, 5), (3, 2), (3, 4), (4, 1), (4,3),(5, 2), (5, 6), (6, 1), (6, 5) }

n(E) = 15.

P(E) = n(E)/n(S) = 15/36 = 5/12.

A : B = 100 : 90.

A : C = 100 : 87.

B/C = (B/A*A/C) = (90/100*100/87) = 30/29

When B runs 30 m, C runs 29 m.

When B runs 180 m, C runs (29/30*180)m =174m

 B beats C by (180 - 174) m = 6 m.

Step (i): Let x be the number of boys and y be the number of girls.
Given total number of boys and girls = 100
x+y=100 -------------- (i)

Step (ii): A boy gets Rs. 3.60 and a girl gets Rs. 2.40
The amount given to 100 boys and girls = Rs. 312
3.60x + 2.40y = 312 -------------- (ii)

Step (iii):
Solving (i) and (ii)
3.60x + 3.60y = 360 --------- Multiply (i) by 3.60
3.60x + 2.40y = 312 --------- (ii)
1.20y = 48
y = 48 / 1.20
= 40

 Number of girls = 40

Let the number of correct answers be X.

Number of incorrect answers = (60 – X).

4x – (60 – x) = 130

=> 5x = 190 

=> x = 38

Let the edge = a cm   

So increase by 50 % = a + a/2 = 3a/2  

Total surface Area of original cube = 6a2  

TSA of new cube = 63a22 =69a24=  13.5a2   

Increase in area = 13.5a2-6a2 =7.5a2  

 7.5a2 Increase % =7.5a26a2×100 = 125%

the next 2 number in series we need to divide the series into 2 different series

First series : 4 , 6, 12, 30 ??

Second Series : 12,18,26, ??

So we need to see for the pattern for those series in order to find the next two number , we can do this by finding the difference or division , multiplication logic whatever may apply :

• Pattern of Series 1 :

6 divide 4 : 1.5

Next number i.e 12 divided by 6=2

Next number i.e 30 divided by 12 =2.5

So series is going in multiples of 1.5, 2, 2.5, 3 , so on

So first series will look like

4 , 6, 12, 30, 30x3 =90

• Pattern of Series 2 : 12,18,26, ??

Its simple Adding numbers with iterative logic (i.e 6, 8, then followed by 10, 12)

Series will be like 12,18,26,36.

For the next two numbers : Series will be like 4, 12, 6, 18, 12, 26, 30, 36, 90