Which value of a will make the following true

The mean temperature for the first 4 days in january was 7°c. the mean temperature for the first 5 days in january was 5°c. what was the temperature on the 5th day?

The sixth grade art students are making a mosaic using tiles in the shape of right triangles. each tile has leg measures of 3 centimeters and 5 centimeters. i f there are 200 tiles in the mosaic what is the area of the mosaic.

Kayla and alberto are selling fruit for a school fundraiser. customers can buy small boxes of grapefruit and large boxes of grapefruit. kayla sold 3 small boxes of grapefruit and 1 large box of grapefruit for a total of $65. alberto sold 1 small box of grapefruit and 1 large box of grapefruit for a total of $55. what is the cost each of one small box of grapefruit and one large box of grapefruit?