Answer:
Step-by-step explanation:
The two-digit numbers are :
10.11.12.13.14.15.16.17.18.19.20.21.22.23.24.25.26.27.28.29.30.31.32.33.34.35.36.37.38.39.40.41.42.43.44.45.46.47.48.49.50.51.52.53.54.55.56.57.58.59.60.61.62.63.64.65.66.67.68.69.70.71.72.73.74.75.76.77.78.79.80.81.82.83.84.85.86.87.88.89.90.91.92.93.94.95.96.97.98.99.
There are 90 two-digit numbers.
The two-digit numbers less than 20 are :
10.11.12.13.14.15.16.17.18.19
There are 9 two-digit numbers that are less than 20.
P(two-digit number less than 20) =