The second volume of mathematics in the sixth grade takes out 15% oil from barrel A and pours it into barrel B. The weight of barrel A is a few percent of that of barrel B..
Solution: Look at the unit "1", then
B barrel oil weight is
1- 15%- 15%
= 1-0. 15-0. 15
=0.7
Barrel a is barrel B.
1÷0.7x 100%≈ 142.86%