If ` 6 @ 4 @ 7 = 101 " and " 2 @ 5 @ 11 = 150 , ` then what is the value of A in `A @ 8 @ 9 = 289 ? `

Options

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

Answer

3

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 `
Therefore ,
`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 (1 ) = 12 `