The nth term of the sequence 3/2, 3, 7, 16, 35, 74 ..... is
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
-7
-9
5
9
Correct answer is B
a*e = a + e + 1 = a
implies e+ 1 = 0
∴ e = -1
7 * e = -1
∴ a + 7 + 1 = -1
a + 8 = -1
a+8 = -1
a = -1-8
a = -9
W ∝ L2 and W = 6 when L = 4. If L = √17 find W
67/8
65/8
63/8
61/8
Correct answer is C
W ∝ L2
W = KL2
K = W/L2
K = 6/42
K = 6/16 = 3/8
W = 3/8 L2
W = 3/8(√17)2
W = 3/8 x 17
W = 51/8 = 63/8
Solve the inequalities -3(x - 2) < -2(x + 3)
x > 12
x < 12
x > -12
x < - 12
Correct answer is A
-3(x-3) < -2(x+3) = -3x + 6 < -2x - 6
-3x + 2x < -6 - 6
-x < - 12
x > -12/-1
x > 12
(2t - 3)(t + 5)
(t + 3)(2t - 5)
(t + 3)(t - 5)
(2t + 3)(t - 5)
Correct answer is B
2t2 + t - 15 = (2t-5)(t+3)