Ask an inequality application problem, kneel down to seek progress! There are 15W books in the library, and a group is arranged to carry the books every day. A total of 1.8W books are moved in two days, and each group is required to carry the same number of books in seven days. How many groups should be arranged at least every day in the next few days? I don't know why the answer is 2.9. How should I list it? I am 1.8 + (0.9 * 5) x > 15

Ask an inequality application problem, kneel down to seek progress! There are 15W books in the library, and a group is arranged to carry the books every day. A total of 1.8W books are moved in two days, and each group is required to carry the same number of books in seven days. How many groups should be arranged at least every day in the next few days? I don't know why the answer is 2.9. How should I list it? I am 1.8 + (0.9 * 5) x > 15

Set at least group A
Each group carries 1.8/2 = 0.9W volume per day
1.8+0.9x（7-2）a≥15
1.8+4.5a≥15
a≥2.93
So arrange at least three groups
Because we should use ≥ sign, because we may finish 15W book by the seventh day