In Grade 4, there are two sections -- Diligence and Industry. The two sections have an equal number of students after 2 students were transferred from section Industry to Diligence. How many students were there in section Diligence before the transfer if, in both sections combined, there are a total of 50 students? Give the rationale and then the answer.
Let's think step by step. There are 50 / 2 = 25 students in each section now. So, there were 25 - 2 = 23 students in section Diligence before 2 students were transferred in their section.. The answer is: 23.

Mikail's birthday is tomorrow. He will be 3 times older than he was when he was three. On his birthday, his parents give him $5 for every year old he is. How much money will they give him? Give the rationale and then the answer.
Let's think step by step. Mikail is 9 because 3 x 3 = 9. He will get $45 because 9 x $5 = $45.. The answer is: 45.

A rectangular plot of private property is fenced in by a chain-link fence. The long sides of the plot are three times the length of the short sides. One short side of the fence is rusted from being hit by a sprinkler and needs to be replaced. If all the sides of the fence together are 640 feet long, how many feet of fence need to be replaced? Give the rationale and then the answer.
Let's think step by step. Let S be the length of the short side of the fence. Thus, the length of a long side of the fence is 3S. There are 2 of each side, so the whole fence is 2S + 2 * 3S = 2S + 6S = 8S long. The whole fence is 8S = 640 feet long. Thus, the short side of the fence that needs to be replaced is S = 640 / 8 = 80 feet long.. The answer is: 80.