Take out 2/7 of the oil in barrel A and pour it into barrel B, so that the weight of the two barrels of oil is equal.

Taking out 2/7 barrels of oil leaves 5/7 barrels of oil, which is as heavy as pouring in 2/7 barrels of oil, indicating that tung oil is 5/7-2/7=3/7.

Then the original weight of barrel B oil is a fraction of that of barrel A, which means barrel B oil: barrel A oil.

(3/7)/ 1=3/7

2. On the first day, 720 *2/5=288 was produced.

The remaining 5/8 will be produced the next day, that is, (720-288)*5/8=270.

Will produce 720-288-270= 162.