All 3,000 seats in a theater are being replaced. so far, 5 sections of 136 seats and a sixth section containing 348 seats have been replaced. how many more seats do they still need to replace?

1972 seats still need to replace.

Step-by-step explanation:

Given,

The total number of seats that have to replaced = 3,000,

Also, total seats in 5 sections of 136 seats = 5 × 136 = 680,

And, total seats in 6th section = 348,

So, the total seats that have already replaced = 680 + 348 = 1028,

Hence, the number of seats that still have to replaced = total seats have to replaced - seats that have already replaced

= 3000 - 1028

= 1972

people went from manufacturing one object at a time by hand to manufacturing many objects in factories