The value of 2 + 4 + 6 +…….+ 2n is
- n(n-1)/2
- n(n+1)/2
- 2n(2n+1)/2
- n(n+1)
The coefficient of x⁶ in (2 + 2x)¹⁰ is
- 10C6
- 2⁶
- 10C6 2⁶
- 10C6 2¹⁰
The coefficient of x⁸y¹² in the expansion of (2x + 3y)²⁰ is
- 0
- 2⁸3¹²
- 2⁸3¹²+2¹²3⁸
- 20C8 2⁸3¹²
If nC10 > nCr for all possible r, then a value of n is
- 20
- 19
- 21
- 10
If a is the arithmetic mean and g is the geometric mean of two numbers, then
- a ≤ g
- a ≥ g
- a=g
- a>g
If (1 + x²)² (1 + x)ⁿ = a₀ + a₁x + a₂x² +……..+ xⁿ⁺⁴ and if a₀, a₁, a₂ are in AP, then n is
- 1
- 2
- 3
- 4
If a, 8, b are in AP, a, 4, b are in GP, and if a, x, b are in HP then x is
- 2
- 1
- 4
- 16
- AP
- GP
- HP
- AGP
The HM of two positive numbers whose AM and GM are 16, 8 respectively is
- 10
- 5
- 6
- 4
If Sᵣ denotes the sum of r terms of an AP whose common difference is d, the value of Sᵣ−Sᵣ₋₁ + Sᵣ₋₂ is
- 0
- 2d
- 4d
- None
The remainder when 38¹⁵ is divided by 13 is
- 12
- 1
- 11
- 5
The nth term of the sequence 1, 2, 4, 7, 11,…….is
- n³ + 3n² + 2n
- n³ - 3n² + 2n
- (n² - n+2)/2
- None
- [√(2n+1)]/2
- [√(2n+1)−1]/2
- √(2n+1)
- √(2n+1)−1]
The nth term of the sequence 1/2 , 3/4 , 7/8 , 15/16 ,……….is
- 2−2ⁿ+1
- 2ⁿ-n-1
- 1−2⁻ⁿ
- 2ⁿ-1
The sum up to n terms of the series √2 + √8 + √18 + √32 +……….is
- n(n-1) / 2
- 2n(n+1)
- n(n+1) / 2
- 1
The value of the series 1/2 + 7/4 + 13/8 + 19/16 +…………. is
- 14
- 7
- 4
- 6
The sum of an infinite GP is 18. If the first term is 6, the common ratio is
- 1/3
- 2/3
- 1/6
- 3/4
The coefficient of x⁵ in the series e^-2x is
- 2/3
- 3/2
- -4/15
- 4/15
The value of 1/2! + 1/4! + 1/6! +……… is
- (e-1)² / 2e
- (e+1)² / 2e
- (e-1)² / e
- (e+1)² / e
- log (5/3)
- 3/2 log (5/3)
- 5/3 log (5/3)
- 2/3 log (5/3)