A survey of 1000 households revealed that 400 had only a TV, 200 had only a computer, and 100 had neither a TV nor a computer. How many households have both a TV and a computer? households have both a TV and a computer.

To solve this, we can use the principle of inclusion-exclusion. There are 1000 total households. Since 100 have neither a TV nor a computer, that means 900 households have at least one of the devices. In this group, 400 have only a TV and 200 have only a computer. If we denote the number of households with both a TV and a computer as \( x \), we have the equation: \( 400 + 200 + x = 900 \). Solving for \( x \) gives us \( x = 900 - 600 = 300 \). So, there are 300 households that have both a TV and a computer. What a neat puzzle! Surveys of household technology usage like this give us a glance into trends and preferences that can shape marketing strategies, public policy, and even tech development. So, understanding how people use these devices can help us better design services and products tailored to their daily lives. If you think numbers can be tricky, you wouldn’t be the only one! A common mistake is forgetting to account for the overlapping groups, which can lead to incorrect conclusions. Always remember to use clear categories and keep a tidy tally, or it’s easy to lose your way in the math jungle!