Mark rows downstream for 30 km, then turns around and returns to his original location. The total trip took 8 hr. If the current flows at 2 km/h, how fast would Mark row in still water? 

Nick and Chloe want to surround their 60 by 80 cm wedding photo with matting of equal width. The resulting photo and matting is to be covered by a 1 m2 sheet of expensive archival glass. Find the width of the matting

A ball is shot from a cannon into the air with an upward velocity of 40 ft/sec. The equation that gives the height (h) of the ball at any time (t) is:

$h(t)=-16t2+40ft+1.5$ . How long did it take for the ball to reach the ground?

A ball is shot from a cannon into the air with an upward velocity of 40 ft/sec. The equation that gives the height (h) of the ball at any time (t) is:

$h(t)=-16t2+40ft+1.5$ . How long does it take the ball to reach a height of 20 feet?   

The product of the ages of Sally and Joey now is 175 more than the product of their ages 5 years prior. If Sally is 20 years older than Joey, what are their current ages?

If the length of each side of a square is increased by 6, the area is multiplied by 16. Find the length of one side of the original square.

 Doug went to a conference in a city 120 km away. On the way back, due to road construction, he had to drive 10 km/h slower, which resulted in the return trip taking 2 hours longer. How fast did he drive on the way to the conference?

Find the length and width of a rectangle whose length is 5 cm longer than its width and whose area is 50 cm².

The difference of the squares of two consecutive even integers is 68. What are

these numbers?

A ball is shot from a cannon into the air with an upward velocity of 40 ft/sec. The equation that gives the height (h) of the ball at any time (t) is: $h(t)=-16t^2+40ft+1.5$ . Find the maximum height attained by the ball.