how far does the tip of the second hand of a clock movie in 25 seconds if its lenght is 7 cm?

Question

how far does the tip of the second hand of a clock movie in 25 seconds if its lenght is 7 cm?

Answer 1

25 seconds = 5 digits on the clock = 5/12 of the circle.

 

5/12 of the circumference = 

5/12 * 2*  pi * 7=

 

5/12 * 2 * 22/7 * 7 =

 

5/12 * 44  <--- 7's cancel

 

5/3 * 11  <--- cancels by 4

 

55/3 =   18 and 1/3 cm