A barrel of oil, the first time to use 2 / 5, the second time to use 3 / 8, the second time to use how much of this barrel of oil?

Use 3 / 8 of this barrel of oil for the second time
Secondary sharing to this barrel of oil = 2 / 5 + 3 / 8 = 16 / 40 + 15 / 40 = 31 / 40

RELATED INFORMATIONS

1. 1 / 8 of 5 meters is equal to a fraction of 1 meter How do you calculate that?
2. Divide the 3-meter-long wire into 8 sections, each of which is 1 meter long______ It's three meters______ ．
3. An 8-meter-long rope is divided into 4 parts of a meter, with an average of () parts. Each part is a fraction of 8 meters, and each part is a fraction of 1 meter What's the percentage of each meter
4. 5 is a fraction of 8
5. B is 5 / 8 of a, and a is a fraction of B
6. What's the ratio of 5 / 8 to 5 / 12
7. What is the proportion of 3 / 8 to 5 / 8?
8. A flat angle equals () right angles, one sixth of the circumference equals () right angles?
9. A circumference is equal to several flat angles, which is several times of a right angle
10. The horizontal angle is equal to []; the perimeter angle is equal to []; 1 ° = [] ', 1' = [] '; 1' = [] '; 1' = [] '
11. According to 1.2 × 4 = 0.6 × 8, it can be written in proportion______ ：______ =______ ：______ ．
12. What is 2.5
13. 12 is a fraction of 34, 11 is a fraction of 34, and 9 is a fraction of 34
14. It takes 12 days to build a 10 meter long road. On average, how many parts of the road and how many meters of the road are built every day/
15. Fraction plus fraction = 5 out of 12
16. 0.12 is a fraction, 0.4 is a fraction
17. What is 21 / 48 of 7 / 12?
18. In 0.9 there are () tenths, which is a few percent. In 0.21 there are () tenths, which is a few percent. In 0.037 there are () Come on, come on, come on, come on, come on, come on, come on, come on, come on, come on, come on, come on, come on, come on, come on, come on In 0.9 there are () tenths, which are fractions. There are () 1% in 0.21, which is a few percent. There are () thousandths in 0.037, what is the percentage
19. When is a fraction = 17
20. 7cm = fraction of decimeter, 17min = fraction of hour, 7jiao = fraction of yuan, 70g = fraction of kg 700 kg = parts of a ton 17 seconds = parts of a minute