Question

the dimensions of a blackboard are 9/10 of a meter by 7/10 of a meter. In drawing of the blackboard given below, 1/2 of a inch represents 2 meters. What is unit rate of area in square meters of the blackboard per square inch of area in the drawing?

Answer 1

16 square meters per square inch

Explanation:

we know that

The scale drawing is

`((1/2))/(2)=(1)/(4)\ (in)/(m)`

That means ---> 1 in in the drawing represent 4 meters in the actual

Find the dimensions of the blackboard in the drawing

Divide by 4

`(9)/(10)\ m=(9)/(10)/4=(9)/(40)\ in`

`(7)/(10)\ m=(7)/(10)/4=(7)/(40)\ in`

Find the area of the blackboard

`((9)/(10))((7)/(10))=(63)/(100)\ m^2`

Find the area in the drawing

`((9)/(40))((7)/(40))=(63)/(1,600)\ in^2`

Find out the unit rate of area in square meters of the blackboard per square inch of area in the drawing

`((63)/(100))/((63)/(1,600))=(1,600)/(100)=16\ (m^2)/(in^2)`