7. a) a school assembly ground is 30m by 30 m. Part of the ground is a cm crete
rectangle of 25m by 5m , while the rest is grass Calculate the area of the grass

The area of the grass is 775 square meters.

Step-by-step explanation:

Area of a Rectangle

A given rectangle of width W and length L has an area of:

A = WL

The school assembly ground has dimensions of 30 m by 30 m, thus its area is:

Aa= 30 m * 30 m = 900 square meters

Inside of it, there is a concrete rectangle of 25 m by 5 m. The area of that rectangle is:

Ac= 25 m * 5 m = 125 square meters

The area of the grass is the difference between those areas:

Ag = Aa - Ac

Ag=900 square meters - 125 square meters

Ag = 775 square meters.

The area of the grass is 775 square meters.

the first option is the answer.