An electronics shop picks every 10th customer to take part in a phone survey to determine their view of the service in the shop. Which sampling strategy is being used? simple random stratified random systematic convenience

Problem melissa is her dad build a walkway in their backyard. the walkway will be 54 feet long and 1.5 feet wide. the local hardware store sells tiles which are 1.5 by 1.5 feet and come in boxes of 12. how many boxes of tiles do they need?