Algebra PlayClass 8 Mathematics MCQs

The 'Think of a Number' trick from the book (Double it, Add four, Divide by two, Subtract original number) gives a final answer of 2. To change the trick so the final answer is 5, which step should be changed?

In the date trick, the final answer is calculated as $100M + 165 + D$. If a person follows the steps and gets a final answer of 590, what was the date they thought of?

For a number pyramid with 4 rows, if the bottom row is represented by the variables [$a, b, c, d$], what is the algebraic expression for the number in the topmost row?