One barrel of oil, two fifths of which were poured out in the first time, and one third of which were poured out in the second time. There are still 52 kg left. How many kg of this barrel of oil were there?

One barrel of oil, two fifths of which were poured out in the first time, and one third of which were poured out in the second time. There are still 52 kg left. How many kg of this barrel of oil were there?

The answer is 390. You set it as X, and the equation is (2 / 15) x = 52. The solution is x = 390. I calculated twice, and that's the answer. You can also divide 52 by 1 / 3, and then divide the number by 2 / 5 to get it. I just registered, and give you some rewards!

A barrel of oil weighs 5000 grams. Two fifths of it is used for the first time and two fifths of kg is used for the second time. How many kg is left?

Because the first 2 / 5 is the fraction, the unit one is known to be 5 kg, and the unit one × who is the specific quantity. The remaining fraction for the first time is 1-2 / 5
The first remaining: 5 × (1-2 / 5) = 3kg
Because the second time is the specific amount, 2 / 5 kg, the specific amount and the specific amount can be directly added and subtracted, so we directly use the first remaining - the second used = the final remaining
The final remaining: 3-2 / 5 = 2.6kg (or fraction: 13 / 5 or 2 and 3 / 5kg)