2 concentric circles have radii 2cm and 3cm respectively, calculate the ratio of their areas

For the first circle the radius is 2cm and for the second circle the radius is 3cm,by taking the ratio of their areas:

πr^2:πR^2

π cancels out and we are left with only r^2:R^2

r=2cm and R=3cm

Therefore r^2:R^2=2^2:3^2

=4:9

The answer is 4:9

Step-by-step explanation:

54 km / hours

step-by-step explanation:

we need to convert seconds to hours

60 seconds = 1 minutes

60 minutes = 1hour

15 m         60 second   60 minutes

  * *         = 54000 meters/ hour

second     1 minute             1 hour

now we need to convert meters to km

1000 m = 1 km

54000 m       1 km

*   = 54 km / hours

hour               1000m