Carlos has \dfrac45 5 4 start fraction, 4, divided by, 5, end fraction of a tank of fuel in his car. He uses \dfrac{1}{10} 10 1 start fraction, 1, divided by, 10, end fraction of a tank per day. How many days will his fuel last? Carlos has \dfrac45 5 4 start fraction, 4, divided by, 5, end fraction of a tank of fuel in his car. He uses \dfrac{1}{10} 10 1 start fraction, 1, divided by, 10, end fraction of a tank per day. How many days will his fuel last? 10