1)A group of students are going on a picnic.The total expenditure will be shared equally among all students.If each student pays $65,they will be $300 short.If each student pays $75,they will have an excess of $100.Find the number of students joining the picnic.
2)John's savings is $300 more than his sister's.After giving $450 of his savings to his sister,John's savings becomes 2/5 of his sister's.How much savings do they have altogether?
3)Consider the equation x-2x+3x-4x+5x-6x+...+99x-100x =200. Solve the equation and briefly explain how you can solve it.
