Clock Problem: A little past 3pm a man decided to take a 20-minute coffee break

Submitted by Catxiee on

A little past 3pm a man decided to take a 20- minute coffee break. When he returned, the minute hand was as much ahead of the hour hand as it was before behind it .what was the time when he decided to take a break?

Jhun Vert Sat, 12/03/2016 - 22:17

$2z + 20/12 = 20$

$2z = 55/3$

$z = 55/6 ~ \text{min}$
 

alg_003-clock-problem.gif

 

$x + z = 15 + x/12$

$11x/12 = 15 - z$

$11x/12 = 15 - 55/6$

$x = 70/11 ~ \text{min} = 6.36 ~ \text{min}$
 

time = 3:6.36 pm       answer