The key to this question is knowing that one mole of any gas occupies 22.4 L at STP (in other words, the volume of one mole of any gas at STP is 22.4 L). So, to figure out the volume of 0.950 g of CO gas, you must figure out how many moles of CO you have.
The molar mass of CO is 28.01 g/mol. So we have 0.950 g CO/28.01 g/mol CO = 0.0339 mol CO gas.
Then we multiply our molar quantity by 22.4, which gives us 0.760 L CO (rounded to three sig figs).