15. Solve the following problems from the last section of the Nine Chapters: (а) A square, walled city measures 200 paces on each side. Gates are located at the centers of each side. If there is a tree 15 paces from the east gate, how far must a man travel out of the outh gate to be able to see the tree? 200 A В 15 F E 100 Н X G A square, walled city of unknown dimensions (b) has four gates, one at the center of each side. A tree stands 20 paces from the north gate. A man walks 14 paces southward from the south gate and then turns west and walks 1775 paces before he can see the tree. What are the dimensions of the city? 268 Chapter 5 T 20 А В Н X E С D 14 1775 G F

The word “unitary” comes from the word “unit”, which means a single and complete entity. In this method, we find the value of a unit product from the given number of products, and then we solve for the other number of products.

Imagine you and 3 of your friends are planning to go to the playground at 6 in the evening. Your house is one mile away from the playground and one of your friends named Jim must start at 5 pm to reach the playground by walk. The other two friends are 3 …

The amount earned or lost on the sale of one or more items is referred to as the profit or loss on that item.

Measurements and comparisons are the foundation of science and engineering. We, therefore, need rules that tell us how things are measured and compared. For these measurements and comparisons, we perform certain experiments, and we will need the experime…