Which statement correctly contrasts lump-sum bids and unit-price bids?

• A. Lump-sum bids a single total price; unit-price bids are based on quantified units and adjust with actual quantities.
• B. Lump-sum bids are based on quantified units and adjust with actual quantities; unit-price bids are a single total price.
• C. Lump-sum is paid per square foot; unit-price is per job.
• D. Lump-sum allows changes without contracts; unit-price does not.

Answer: (A)

The key idea is how pricing is determined in different bids. A lump-sum bid sets one fixed total price for the entire painting project, regardless of the actual quantities encountered. The contractor commits to completing everything for that single amount, and any cost differences fall on them unless the contract allows adjustments. A unit-price bid, on the other hand, prices work by quantified units (for example, price per square foot of painted wall). The final contract amount is the sum of those unit prices times the actual quantities measured in the field, so the total can change as quantities are known or vary.

That’s why the statement describing lump-sum as a single total price and unit-price as based on quantified units that adjust with actual quantities is the best fit. The other ideas misstate the relationship—unit-price isn’t inherently a “per job” price, lump-sum isn’t driven by per-unit quantities, and changes typically involve formal contract amendments rather than automatic adjustments.