It looks like you've uploaded a detailed question paper with various topics covering Time, Speed, Distance, Work and Time, Unit Digits, and Averages. Here are brief summaries and explanations for each section:

Time, Speed, Distance

These problems involve calculations on time, speed, and distance. Key concepts:

1. Speed = Distance / Time
2. Time = Distance / Speed
3. Distance = Speed x Time

You'll need to apply these formulas to solve each question based on the given parameters (e.g., speed, distance, and time).

Work and Time

These problems involve calculating the time required to complete work based on the efficiency of workers.

1. Efficiency is inversely proportional to time: More workers = Less time.
2. For combined work, you add the rates of the workers: 1/A + 1/B = 1/T, where A and B are the individual times, and T is the combined time.

Unit Digits

To find the unit digit of powers, look for repeating cycles in powers of numbers:

1. For example, the powers of 2 (2^1, 2^2, etc.) have a cycle of 4 (i.e., 2, 4, 8, 6, and repeats).
2. Similarly, find the repeating pattern for other numbers to determine the unit digit of large powers or products.

Average

The average is the sum of values divided by the number of values. You can apply this formula to find the average of various data points, as well as to work with changes in averages when new values are added or removed.

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