AG Mechanics CDE Practice Exam

A 1-2-3 mixture of concrete means:

1. 1 part sand, 2 parts gravel, 3 parts water

2. 1 part cement, 2 parts sand, 3 parts gravel

3. 1 part water, 2 parts sand, 3 parts cement

4. 1 part gravel, 2 parts cement, 3 parts sand

The correct answer is: 1 part sand, 2 parts gravel, 3 parts water

A 1-2-3 mixture of concrete means that it consists of 1 part cement, 2 parts sand, and 3 parts gravel. This is a commonly used ratio in construction to achieve a strong and durable concrete mix. Option B, 1 part cement, 2 parts sand, 3 parts gravel, is the correct combination for a 1-2-3 mixture of concrete. This mixture provides a balance of cement for strength, sand for workability, and gravel for durability in the final concrete structure. Options A, C, and D do not follow the standard 1-2-3 mixture ratio, making them incorrect choices for this question.