As an estimation we are told 5 miles is 8 km. Convert 17.8 km to miles.

17.8km = 11.125 miles

Step-by-step explanation:

From 5 miles = 8km, we can form the ratio km:miles as 8 : 5.

We want to put the ratio in the form 1 : n, which gives us 1 : 0.625 (we divide both 8 and 5 by 8 to get this form).

Now, using the ratio km:miles as 1:0.625, we have to multiply both 1 and 0.625 by 17.8 to gain the ratio 17.8 : n, therefore giving us the ratio 17.8 : 11.125.

Hence, 17.8km = 11.125 miles

11.125 miles

Step-by-step explanation:

Proportions:

5 miles ⇒ 8 km

A miles ⇒ 17.8 km

A = 17.8km*5miles/8miles

A = 11.125 miles