Grades 9-10 Video Solutions 2020-Levels 9&10 Video Solutions 2020

Video Transcription
Video Summary
The transcript provided appears to be a series of problems and solutions for a math competition or similar academic activity. Each problem is presented, explained, and solved in a clear, systematic manner. The problems range from basic arithmetic calculations to more complex geometry and logic puzzles.<br /><br />1. The first problem involves determining the perimeter of a composite shape made from squares and solving it with a correct solution of 18 centimeters.<br /><br />2. The second problem gives a list of simple arithmetic operations and asks which result is in the middle once sorted, leading to the solution of 1,239.<br /><br />3. The third problem involves a logic puzzle about family relationships, deducing that Anne’s grandmother is the answer.<br /><br />4. The fourth question is a logic puzzle involving clothing pattern alignment, concluding that there are zero rings around Cosmo’s waist when the shirt is buttoned incorrectly.<br /><br />5. The fifth problem involves algebraic manipulation and matching mathematical expressions, revealing a sum of 158 for the right-side calculations.<br /><br />6. The sixth involves algebra and simple sequences, resulting in identifying the smallest integer of a sequence being -1.<br /><br />7. Problem number seven concerns determining when the next year with a repeated digit pattern will occur, calculated to be 101 years after 2020.<br /><br />8. The eighth question addresses counting specific paper shapes after making cuts, determining Mary initially had 4 triangles.<br /><br />9. Problem number nine involves geometrical reasoning about a kite and uses triangle properties to find the pole's initial length, with a solution of 400 cm.<br /><br />10. The tenth problem is geometric and spatial, determining the smallest triangular area, solved as 1/2.<br /><br />11. The eleventh question is a planning problem to maximize story days spent with a grandmother, resolved with a start day on Saturday.<br /><br />12-30. The following problems similarly cover a variety of topics, including divisibility, geometry, logic, probability, and algebra, each with a concise solution and explanation, such as determining the smallest angle, maximizing conditions for cubes painted, and calculating values for specific grid cell entries.<br /><br />Overall, the document demonstrates mathematical problem-solving across a range of subjects, with an emphasis on logical reasoning and algebraic manipulation. The solutions provide direct answers, often accompanied by verification steps to ensure accuracy.
Keywords
math competition
problem-solving
geometry
arithmetic
logic puzzles
algebra
sequence
geometrical reasoning
triangular area
divisibility
probability
algebraic manipulation