1. Quant concept I learned today
Today's GMAT Quant takeaway: Range questions are much easier once you remember that the combined range can never be smaller than the largest individual range. When the ranges can overlap completely, the smallest possible combined range is simply the larger range.
2. Number properties
Today's number properties lesson: When k4 is divisible by 32=25, focus on the number of factors of 2 rather than calculating huge powers. Since the exponent gets multiplied by 4, k needs at least two factors of 2 → k must be divisible by 4.
3. Data Sufficiency
DS takeaway: For percentage questions, always identify the numerator and denominator. One statement may give you the change in income while another gives you the tax amount. Individually insufficient + individually insufficient can become sufficient together.
4. Biggest lesson today
Today's GMAT lesson: A lot of Quant questions aren't testing difficult calculations—they're testing whether you can translate the wording into the right mathematical relationship. Slowing down and identifying exactly what the question is asking has helped me more than trying to calculate faster.