Question

Jose unlocks his cellphone by placing his right thumb on a square of 1 centimeter by 1 centimeter at the center of the screen. Upon recognizing his thumbprint, the square expands outward. The cellphone unlocks when the perimeter reaches 32 centimeters, taking a total of 2.5 seconds. What is the perimeter of the square after 1.5 seconds? 16.8 centimeters 19.2 centimeters 20.8 centimeters 29.2 centimeters

Answer 1

Explanation:

We can solve this question using proportion

Perimeter of the square/Time is takes to unlock

We are told in the question that:

The cellphone unlocks when the perimeter reaches 32 centimeters, taking a total of 2.5 seconds.

Hence, the perimeter of the square after 1.5 seconds is:.x = unknown

32/2.5 = x/1.5

Cross Multiply

2.5x = 32 × 1.5

x = 32 × 1.5/2.5

x = 19.2 centimeters