Question

If a 40-foot tree casts a 12-foot shadow, find the length of the shadow cast by a 28-foot tree

Answer 1

The shadow cast by a 28-foot tree is 8.4 foot.

Explanation:

The rule of three is a way of solving problems of proportionality between three known values and one unknown, establishing a relationship of proportionality between all of them. In the case of direct proportionality, when one magnitude increases, the other increases ( or if one magnitude decreases, the other will also decrease)

This is an example of application of this rule:

40 foot tree ⇒ 12 foot shadow

28 foot tree ⇒ x foot shadow

Then, to solve and calculate the value of x, which is the value of the shadow cast by the 28-foot tree, perform the count:

x=
`(28*12)/(40)`

x=
`(336)/(40)`

x=8.4

This means that the shadow cast by a 28-foot tree is 8.4 foot.

Answer 2

12/40 =0.3

28 *0.3 = 8.4

it will cast a 8.4 foot long shadow