Downstream 280mi/7 hours
(Speed =change in position/change in time)
40mi/hr
Back
280/14
20mi/hr
P + r = 2.50
r = p + 1
p + p + 1 = 2.50
2p + 1 = 2.50
2p = 2.50 - 1
2p = 1.50
p = 1.50/2
p = 0.75 <=== pencil cost 75 cents
r = p + 1
r = 0.75 + 1
r = 1.75 .....ruler cost 1.75
We know, length of arc = Ф/360 * 2πr
= 15/360 * (2 * 3.14 * 20)
= 1/24 * (125.6)
= 5.23
In short, Your Answer would be 5.23 Inches
Hope this helps!
The first one u circled is a single rotation