The weight of gaseous mixture containing $6.02\times {10}^{23}$ molecules of nitrogen and $3.01\times {10}^{23}$ molecules of sulphur dioxide is:

The correct option is C 60
The molar masses of nitrogen and sulphur dioxide are $28$ g/mol and $32$ g/mol respectively.
$6.02\times {10}^{23}$ molecules of nitrogen corresponds to $1$ mole or $28$ g.
$3.01\times {10}^{23}$ molecules of sulphur dioxide corresponds to $0.5$ mole or $32$ g.
Hence, the weight of the gaseous mixture is $28g+32g=60g$.