Answer: 120 lb of potatoes.
Explanation:
Let the pounds of potatoes sold by farmer Bill = X lb
Fractional part sold to the first person = 1/4
Therefore 1/4 of X = 1/4 x X
= X/4 lb of potatoes.
No of potatoes left for sale = X - X/4
= ( 4x - x )/4
= 3x/4 lb.
Fractional part sold to the second person out of the reminder = 4/9
Therefore 4/9 of 3x/4 = 4/9 x 3x/4
= x/3 lb of potatoes.
Amount of potatoes left for sale = 3x/4 - x/3
Resolve into fraction , we have = (9x - 4x)/12, because 12 is the LCM.
= 5x/12
Third buyer bought 4/5 of the left over = 4/5 of 5x/12
= x/3 lb of potatoes.
Amount of potatoes left = 5x/12 - x/3
Resolve in to fraction again taking 12 as the LCM = ( 5x - 4x )/12
= x/12 lb of potatoes .
Therefore, the left over was 10 lb .
To determine the value of x now which correspond to the amount of potatoes sold by Farmer Bill, we shall the equate the left to x/12 = 10
we now cross multiply to get the value of x x = 120 lb.
therefore the pound of potatoes sold by farmer Bill = 120 lb.