1. A boat sailed from P to Q in 20 mins, and then it sailed from Q to R in 10mins.
Given that QR = 3km, QP = 4km and PR is the longest one.
a(i) Find the average speed of the boat in the course the boat sailed from P to Q.
(ii) Find the average speed of the boat in the course the boat sailed from Q to R.
(iii) Find the average speed of the boat in the course the boat sailed from P to R.
(b) Find the average velocity of the boat in the
更新1:
course the boat sailed from P to R.
