Question
if a2 + b2 +
c2Â =Â 2(3a -5b -6c)-70 , then a-b-c = ?Solution
a2 + b2 + c2 = 2(3a -5b -6c)-70 So a2 + b2 + c2 -2×3a +2 ×5b + 2×6c +70 = 0 a2 -2×3a +9 + b2 +2 ×5b+25 +c2 +2×6c+36 = 0 So (a-3)2 +(b+5)2+(c+6)2 = 0 As we know that if x2 + y2 +z2 = 0 then x=y=z = 0 So here a-3 = 0 so a =3; b +5 = 0 so b = -5 And c+6 =0 so c = -6 So now a-b-c = 3-(-5)-(-6) = 3+5+6 = 14
- Find the wrong number in the given number series.
25, 36, 29, 40, 33, 50 154Â Â Â Â 165Â Â Â Â 143Â Â Â Â 175Â Â Â Â Â 132Â Â Â Â Â 187
...5000, 4500, 3600, 2480, 1512, 756Â Â Â
Find the wrong number in the given number series,
125, 150, 250, 475, 875, 1500
- Find the wrong number in the given number series.
5, 8, 12, 19, 27, 39 768Â Â Â 2304Â Â Â 288Â Â Â 864Â Â Â 106Â Â Â 324
Find the wrong number in the given number series.
5, 6, 14, 45, 188, 925
120, 240, 80, 320, 60, 384
21 32 54 86 131 186
... 7    12     33    126    635  Â
