The value of `5^2+6^2+ddot\ +10^2+20^2i s` 755 (b) 760 (c) 765 (d) 770

If a=7,\ b=5,\ c=3, then the value of a^2+b^2+c^2-a b-b c-c a\ i s -12 (b) 0 (c) 8 (d) 12

If a=7, b=5, c=3, then the value of a^2+b^2+c^2-a b-b c-c a i s -12 (b) 0 (c) 8 (d) 12

The mean of 1^2, 2^2, 3^2, 4^2, 5^2, 6^2, 7^2 is (a) 10 (b) 20 (c) 30 (d) 40

Find the value of (-2)^-5 times (-2)^6 is (a) 2 (b) -2 (c) -5 (d) 6

The value of ((75.8)^(2)-(55.8)^(2))/(20) is (a) 20 (b) 40( c) 121.6( d )131.6 is (a) 20 (b)

Let a_(1),a_(2),a_(3)"……." be an arithmetic progression and b_(1), b_(2), b_(3), "……." be a geometric progression sequence c_(1),c_(2),c_(3,"…." is such that c_(n)= a_(n) + b_(n) AA n in N . Suppose c_(1) = 1, c_(2) = 4, c_(3) = 15 and c_(4) = 2 . The value of sum of sum_(i = 1)^(20) a_(i) is equal to "(a) 480 (b) 770 (c) 960 (d) 1040"

If a and b be positive integers such that a^2-b^2=19 , then the value of a is 9 (b) 10 (c) 19 (d) 20

If the mean of the following observation be 56.5, find the value of m. Options are (a) 10 (b) 20 (c) 12 (d) 2.

If [(2a+b,a-2b),(5c-d,4c+3d)]=[(4,-3),(11,24)] then the value of a+b-c+2d is (a) 8 (b) 10 (c) 4 (d) -8

Derivative of x^2-2 at x=10 is ………..a)10 b)20 c)-10 d)-20