Let m and n (m < n) be the roots of the equation x2 – 16x + 39 = 0. If four terms p, q, r and s are inserted between m and n to form an AP, then what is the value of p + q + r + s ?
29
30
32
35
A geometric progression (GP) consists of 200 terms. If the sum of odd terms of the GP is m, and the sum of even terms of the GP is n, then what is its common ratio ?
m/n
n/m
m + (n/m)
n + (m/n)
If the roots of the equation
a(b - c)x2 + b (c – a)x + c(a - b) = 0
are equal, then which one of the following is correct ?
a, b and c are in AP
a, b and c are in GP
a, b and c are in HP
a, b and c do not follow any regular pattern
What is the value of 1 – 2 + 3 – 4 + 5 - ... + 101 ?
51
55
110
111
A.
51
Given expression: 1 – 2 + 3 – 4 + 5 -... + 101
Arrange the given terms in pairs : (1 – 2) + (3 – 4) + (5 - ... + 101
Then we get, - 1 - 1 - 1 - 1 ... 50 times + 101
⇒ - 50 + 101 = 51
Option A is correct.
Arithmetic meanof 10 observation is 60 and sum of squares of deviations from 50 is 5000. What is the standard deviation of the observation ?
20
21
22, 36
24, 70
If (1 + 2x – x2)6 = a0 + a1x + a2x2 + ... + a12x12, then what is a0 – a1 + a2 – a3 + a4 - ... + a12 equal to ?
32
64
2048
4096