The perimeter of a rectangular garden is 90 m. If the width is 7 m less than the length, find the length of the garden.

Four of the angles of a hexagon sum up to 420º. If the remaining angles are equal, find the value of each of the angles.

Find the value of x in the diagram above.

The following are the masses (in kg) of members in a club: 59, 44, 53, 49, 57, 40, 48, and 50. Calculate the mean mass.

The following are the masses (in kg) of members in a club: 59, 44, 53, 49, 57, 40, 48, and 50. Calculate the variance of the distribution.