5 . 2n-2 - n
5 . 2n-2 - (n+1) / 2
3 . 2n-2
3/2 n
Correct answer is A
3/2, 3, 7, 16, 35, 74, ....
Using the method of substitution
When n = 1, 5 . 2n-2 - 1 = 5 . 21-2 - 1
= 5 x 2-1 - 1
= 5 x 1/2 - 1
= 5/2 - 1 = 3/2
When n = 1, 5 . 2n-2 - n
= 5 . 22-2 - 2
= 5 x 20 - 2
= 5 x 1 – 2 = 3
When n = 3, 5 . 2n-2 - n
= 5 . 23-2 - 3
= 5 x 21 - 3
= 5 x 2 – 3
= 10 -3 = 7
When n = 4, 5 . 2n-2 - n
= 5 . 24-2 - 4
= 5 x 22 - 4
= 5 x 4 – 4
= 20 – 4 = 16
When n = 5, 5 . 2n-2 - n
= 5 . 25-2 - 5
= 5 x 23 - 5
= 5 x 8 – 5
= 40 – 5
= 35
When n = 6, 5 . 2n-2 - n
= 5 . 26-2 - 6
= 5 x 24 - 6
= 5 x 16 – 6
= 80 – 6 = 74
∴ 5 . 2n-2 - 1 = 3/2, 3, 7, 16, 35, 74
A binary operation ⊗ defined on the set of integers is such that m⊗n = m + n + mn for ...
If events X and Y are mutually exclusive, P(X) = 1/3 and P(Y) = 2/5, P(X∪Y) is ...
An arc of a circle of radius 6cm is 8cm long. Find the area of the sector...
A regular hexagon is constructed inside a circle of diameter 12cm. The area of the hexagon is ...
If O is the centre of the circle in the figure, find the value of x ...
Given that x2 + y2 + z2 = 194, calculate z if x = 7 and \(\sqrt{y}\) = 3...
A straight line makes an angle of 30° with the positive x-axis and cuts the y-axis at y = 5. Fin...
Evaluate 3(x + 2) > 6(x + 3)...
The chord ST of a circle is equal to the radius r of the circle. Find the length of arc ST ...