Laura took six trips to park. On each trip, she spent 2 hours at the park and an additinal 30 minutes walking to and from the park. What percentage of the total time she took for her trips to the park did Laura spend in the park? Give the rationale and then the answer.
Let's think step by step. During 6 days, Laura would spend 2 * 6 = 12 hours in the park. If it takes 30 minutes (or 0.5 of an hour) walking to and from the park, then for the six trips, it would take her an additional 0.5 * 6 = 3 hours to walk to and from the park. In total, she would spend a total of 12 + 3 = 15 hours on her six trips. So, the fraction of time spent in the park would be 12 / 15 = 0.8. Thus, converting fraction to percentage, Laura spent 0.8 * 100% = 80% of her trip time at the park.. The answer is: 80.

Mary goes with her 3 children to the circus. Tickets cost $2 for adults and $1 for children. Mary pays with a $20 bill. How much change will she receive? Give the rationale and then the answer.
Let's think step by step. Mary's ticket costs $2 / ticket * 1 ticket = $2. Mary's children's tickets cost 3 tickets * $1 = $3. Together the tickets cost $2 + $3 = $5. After paying with a 20 - dollar bill, Mary will receive $20 - $5 = $15.. The answer is: 15.

It takes 7 years for an apple tree to bear fruit. If Lydia planted a tree when she was 4 years old and is now 9 years old, how old would she be when she gets to eat an apple from her tree for the first time? Give the rationale and then the answer.
Let's think step by step. The tree has been planted for 9 - 4 = 5 years. It will take another 7 - 5 = 2 years for it to bear fruit. Lydia will be 9 + 2 = 11 years old.. The answer is: 11.