Question

I need help!!! How to do I start or solve it?

Answer 1

(a) 1: 600

(b) Height on the drawing = 12.5 cm

Explanation:

When we say scale is x cm to y m we write it as x : y

Algebraically this is the same as
`(x)/(y)`

(a) Scale is expressed as 5cm: 30 m

Dividing by 5 we get scale as 1 cm : 6 m

Since we need to express it as 1 : n, we have to convert to same units
--> 1 m = 100 cm
--> so 6 m = 600 cm

--> Scale is 1 cm: 6 m = 1 cm :6 00 cm or 1: 600

(b) We are given actual building height as 75 m.
Convert to cm: 75 m = 75 x 100 = 7500 cm

Using the fact that the ratio 1 : n can be expressed as
`(1)/(600)` we get

`(x\;cm)/(7500\;cm) = (1)/(600)`

where x is the height in the drawing in cm

Multiply both sides by 7500 to get

`\textrm{x\;cm = $(1* 7500\;cm)/(600)$ = 12.5 cm}`

Height on the drawing = 12.5 cm