Quantitative Aptitude - Arithmetic Ability Questions

sin 46. cos 44+ cos 46. sin 44

sin 46. sin (90 -44)+ cos 46. cos (90 -44)

= sin^2 46 + cos^2 46

= 1

Cp1 = p2 - p1 ,
Cp2 = p3 - p2
..
..
..
Cp23 = p24 - p23
Sum of series = (p2-p1) + (p3-p2) + .....(p23-p22) + (p24-p23)
All terms get cancelled, except p1 = 2 and p24 = 89
So Sum = -p1 + p24
Sum of series = -2 + 89 = 87

All powers of 6 has 6 in units place so answer will definitely be 1.

Let the number be x. Then, x - 3x/5 = 50  <=>  x = (50 * 5) / 2 = 125..

12% of 70,000

=> 12 x 70,000/100

=> 8400

Hence, 12% of 70,000 = 8,400

Ans. C.
Let 4 consecutive even numbers are x, x+ 2, x+ 4, x+ 6
According to the question -
1/x + 1/x+2 = 11/60
x+2+x/ x(x+2) = 11/60
2(x+1)/x^2 + 2x = 11/60
120x + 120 = 11x 2 + 22x
11x 2 - 98x – 120 = 0
So ,
X = -24/22 , 10
X = -12/11 , 10
So, the numbers will be 10,12,14,16.
Hence,
Third largest number = 14
Reciprocal of third number = 1/14

For a triangle, we need 3 non-collinear points. So with 12 points (when all the 12 are such that any three non-collinear is12C3. But among them 8 points are collinear.

If all these 8 points are different we get 8C3 triangles as they are collinear.

In 12C3 triangles, we do not get 8C3 triangles

Therefore, The number of triangles we get = 12C3-8C3 = 164