Speed of the ship in the second hour = (62.5 * x ) / 100 kph.
In third hour it is [(62 * x) / 100 ] * x/100]
is 4th hour its is the above * x/100 again so we can now form the equation
62.5x x x
------- * ---- * ---- = 32
100 100 100
62,5 x^3 = 32,000,000
x^3 = 512,000
x = 80 <----- Answer to (a)
(b) Ship travels 62.5 in first hour then this falls by a common ratio of 0.8 each hour so we have a geometric sequence
Dist travelled in 6 hours = a1 1 - r^n
-------- = 62.5* (1 - 0.8^6) / 1 -0.8 = 230.56
1 - r
Answer is 230.56 km
