If a2 + b2 + c2 = 16, x2 + y2 + z2 = 25 and ax + by + cz = 20, then the value of 
Show answer & explanation
Correct answer: C
Explanation
The correct option is 3.
a2 + b2 + c2 = 16, x2 + y2 + z2 = 25 and ax + by + cz = 20
let a = 0, b = 0, x = 0, y = 0
we get
02 + 02 + c2 = 16, c2 = 16, c = 4
02 + 02 + z2 = 25 , z2 = 25, z = 5
putting value of c and z
0x + 0y + cz = 20
satisfy the above equation
putting the values
