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
Less, 12 x 3/4 is 9 as you take 12/4 which is 3 times 3, which gives you 9
2x^2 + 8x - 12 = 0..divide by 2
x^2 + 4x - 6 = 0
x^2 + 4x = 6...add 4 to both sides of the equation
x^2 + 4x + 4 = 6 + 4
(x + 2)^2 = 10....<== ur constant is 10
x + 2 = (+-)sqrt 10
x = -2 (+ - ) sqrt 10
x = -2 + sqrt 10
x = -2 - sqrt 10
