यदि `6" ""@"" "4" ""@"" "7" "=101"तथा " 2" ""@"" "5" ""@"" "11 = 150` है , तो A @ 8 @ 9 = 289 में ,A का मान क्या है ?

Options

A. 5
B. 8
C. 12
D. 17

Answer

C

Explanation

`6" ""@"" "4" ""@"" "7 = 101`
`rArr(6)^(2) + (4)^(2) + (7)^(2) = 101`
`rArr 36 + 16 + 49 = 101`
`2" ""@"" "5" ""@"" "11 = 150`
`rArr (2)^(2) + (5)^(2) + (11)^(2) = 150`
`rArr 4 + 25 + 121 = 150`
अतः ,
`A" ""@"" "8" ""@"" " 9 = 289`
`rArr (A)^(2) +(8)^(2) +(9)^(2) = 289`
`rArr (A)^(2) + 64 + 81 = 289`
`rArr (A)^(2) = 289 - 145 = 144`
`:. A = sqrt(144) = 12`