Question

The two cones below are similar. What is the height of the smaller one?

Answer 1

Answer:

D. $\frac{20}{7}$

Step-by-step explanation:

When two solid same type figures are similar then their corresponding measures are in same proportion,

i.e. if a cone having radius $r_1$ and height $h_1$ is similar to the cone having radius $r_2$ and height $h_2$.

Then,

$\frac{r_1}{r_2}=\frac{h_1}{h_2}$

Here,

$r_1=7, r_2=4, h_1 = 5, h_2 = x$

By substituting the values,

$\frac{7}{4}=\frac{5}{x}$

$7x = 20$

$\implies x = \frac{20}{7}$

Hence, the height of smaller one is 20/7 units.

Answer 2

Answer:

D. 20/7

Step-by-step explanation:

Since

4/7 = x/5

Multiply the left side by x and the right side by 4 as shown below

7*x = 4*5

7x = 20

Then dividing both sides by 7 would cancel on the left

7x/7=x

X = 20/7