SOLUTION: Please help me to answer this it is really hard and i don't know what to do, thank you! Uhmm, sorry but i don't know what type of question is this, sorry!. Twenty-five potatoes are

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Question 22958: Please help me to answer this it is really hard and i don't know what to do, thank you! Uhmm, sorry but i don't know what type of question is this, sorry!. Twenty-five potatoes are placed on the ground 4 feet apart in a straight row. In line with the potatoes and 10 feet from the first one is a basket. A runner starting from the basket picks up the potatoes and carries them one at a time to the basket. if he runs at an average rate of 5 yards per second, how many potatoes can he put into the basket in one minute and 16 seconds??
Answer by venugopalramana(3286) (Show Source):
You can put this solution on YOUR website!
speed= 5 yards per second=5*3= 15 fps
time = 1 mt. 16 sec.= 60 +16 = 76 sec.
distance covered =speed *time = 15*76 = 1140 feet
POTATOES NUMBERS
basket 1 2 3 4 5 6 7......
distance 10 4 4 4 4 4 4......
totdis.frm bask.10 14 18 22 26 30 34......
distance covered to basket potato 1 = 10+10 = 2*10
distance covered to basket potato 2 = 14+14 = 2*14
distance covered to basket potato 3 = 18+18 = 2*18
distance covered to basket potato 4 = 22+22 = 2*22
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TOTAL DISTANCE COVERED=2*10+2*14+2*18....=2(10+14+18+....)=1140
this is an arithmatic progression.FIRST TERM =A =10
COMMON DIFFERENCE =D=4
NO.OF TERMS = N = ?
SUM = 1140/2=570 FEET = (N/2){2A+(N-1)D)=(N/2)(2*10+(N-1)4)=(N/2)(20+4N-4)=
(N/2)(4N-16)=2N(N-4)=570
N(N-4)=570/2
N^2-4N-285=0
N^2-19N+15N-285=0
N(N-19)+15(N-19)=0
(N-19)(N+15)=0
N-19=0
N=19
SO HE PICKS 19 POTATOES