Question

Jerry has a miniature model of a boat. He knows that the boat is 3 3/4 inches wide and 5 1/2 inches long. What is the actual length of the boat if the actual width is 15 feet?

Answer 1

Width of the miniature model =
`3(3)/(4)` inches

Length of the miniature model =
`5(1)/(2)` inches

The actual width of the boat = 15 feet

Let us find the actual length of the boat.

Write it in a proportion form.

width of model : length of model : : width of actual : length of actual

`$\Rightarrow 3(3)/(4):5(1)/(2)::15:x`

`$\Rightarrow(15)/(4):(11)/(2)::15:x`

`$\Rightarrow((15)/(4))/((11)/(2)) =(15)/(x)`

Do cross multiplication.

`$\Rightarrow{(15)/(4)x =15*(11)/(2)`

`$\Rightarrow{(15)/(4)x =(165)/(2)`

`$\Rightarrow x =(165)/(2)*{(4)/(15)`

⇒ x = 22

Hence the actual length of the boat is 22 feet.