Agroup of friends went on a holiday to a hill station. it rained for 15 days. but when it rained in the morning, the afternoon was lovely. and when it rained in the afternoon, the day was preceded by clear morning. altogether there were 12 very nice mornings and 13 very nice afternoons. how many days did their holiday last?

Asix-sided die of unknown bias is rolled 20 times, and the number 3 comes up 6 times. in the next three rounds (the die is rolled 20 times in each round), the number 3 comes up 6 times, 5 times, and 7 times. the experimental probability of rolling a 3 is 10 %, which is approximately % more than its theoretical probability. (round off your answers to the nearest integer.)