\( \$ 750 \) at \( 6 \% \) for 18 months \( \begin{array}{lll}\text { T. } \$ 58.50 & \text { U. } \$ 67.50 & \text { V. } \$ 56.75\end{array} \)

To find the interest earned on \( \$750 \) at \( 6\% \) for \( 18 \) months, you can use the formula for simple interest, which is \( I = P \times r \times t \). Here, \( P \) is the principal amount (\$750), \( r \) is the rate (6% or 0.06), and \( t \) is the time in years (1.5 years for 18 months). Calculating, you get: \[ I = 750 \times 0.06 \times 1.5 = 67.50 \] So, the interest earned is \( \$67.50 \). During the early days of banking, simple interest was the standard method for calculating returns on investments or loans. It allowed both banks and borrowers to have a clear understanding of how much money would accrue over time. The concept of interest has evolved, but the foundational principles remain the same, which is why simple calculations like these form the backbone of financial literacy today. In the real world, knowing how to calculate interest is essential when making investment choices or comparing loans. Many people overlook this by not considering the total cost of borrowing. Ensure to always calculate the interest or the return on investment before committing—this small but necessary step can save you from finance-related mistakes in the future!