Mary went up the Old Tower taking 3 steps per second. Then she carefully came down from the tower taking 2 steps per second. It took Mary 25 seconds longer to come down than to go up. How many steps does the Old Tower have?

150 steps

Step-by-step explanation:

GOING UP:

Steps taken per second = speed = 3steps/s

Let Time taken = y

Number of steps = steps taken per second × time taken

Number of steps = 3 × y - - - - (1)

COMING DOWN:

Steps taken per second = 2steps/s

Total time taken = y + 25

Number of steps = 2 × (y + 25)

Number of steps = 2y + 50 - - - - - (2)

Equating (1) and (2)

3y = 2y + 50

3y - 2y = 50

y = 50

Substitute y = 50 into either (1) or (2)

Put y= 50 into (1)

Number of steps = 3y

Number of steps = 3(50)

Number of steps = 150

you need to rotate this triangle about the origin 270 degrees clockwise to create the full square.