To solve this problem, we first need to find each of their hourly rates. We can do this by dividing the boxes by the number of hours. Using this method, we get that Jack wraps 14 boxes per hour and Walter wraps 12 boxes per hour. So, since the question has them working together, the rate is the sum of each of their individual rates per hour. Since we know that they work for t hours, we can multiply their combined rate by t (since in a job problem, job = time * rate). And, on the other end of the equal sign, since we know that they wrapped 65 presents, we put 65 there. The equation becomes:
This one is a little tricky because of the conversion but .51 cm converts to roughly .2 inches (actually its .200787 but we will round to .2 for ease of math). 4 in/.2in = 20
Therefore the tree is 20 years old.
Footnote 1cm is equal to .3937 inches so it would be .51cm * .3937in = .200787in
The radius is always half of the diameter so half of 17 is 8.5. 8.5x3.14 is 26.69. Then you add 26.69+26.69 to get the answer. (I’m not positive that this is correct)