3 6/10 +5, 9

To add the numbers \(3 \frac{6}{10}\) and \(5.9\), we first convert \(3 \frac{6}{10}\) into an improper fraction or a decimal.

1. Convert \(3 \frac{6}{10}\) to a decimal: \[ 3 \frac{6}{10} = 3 + 0.6 = 3.6 \]

2. Now add \(3.6\) and \(5.9\): \[ 3.6 + 5.9 = 9.5 \]

So, \(3 \frac{6}{10} + 5.9 = 9.5\).