If the binary operation `o.` is defined on the set `Q^+` of all positive rational numbers by `ao.b=(a b)/4dot` Then, `3o.(1/5o.1/2)` is equal to `3/(160)` (b) `5/(160)` (c) `3/(10)` (d) `3/(40)`

Explanation

`frac{3}{160}`

Given :` a odot b=frac{a b}{4}`
`

(frac{1}{5} odot frac{1}{2})=3 odot[frac{(frac{1}{5})(frac{1}{2})}{4}]`


`=3 odot(frac{1}{40})`

`=frac{3(frac{1}{40})}{3^{4}}`

`=frac{3}{160}`