Insert grouping symbols to make the number sentence true 16÷2×4-3 = 8

If 20% of a number is 35, what is 50% of that number?

Through which points should a line of rotation be placed to create a cylinder with a radius of 3 units

Sean is his dad build a tiled walkway in their backyard. the walkway will be 6060 feet long and 22 feet wide. the local hardware store sells tiles which are 22 by 22 feet and come in boxes of 66. how many boxes of tiles do they need?