Write a system of linear inequalities to model the given real-life situation. 1. A calamansi juice (c) and a slice of buko pie (b) cost at most P60. A slice of buko pie's price is at most 5 times the price of a calamansi juice. 2. A group of tourists is planning a trip to Boracay this December. At least 12 people must sign up for the trip, or it will be cancelled. The number of boys (x) in the group is at most twice the number of girls. 3. The daily allowance of Anne (a) is at most ten more than twice the allowance of her sister, Rowena (r). Together, they are given at most Php100 a day. 4. A house (h) and lot (l) together in a subdivision cost at least Php 800,000. A house is more than thrice the cost of a lot.