SOLUTION: the average of 15 men in a boat is increased by 3 kg when one of the crew who weights 40kg, is replaced by someone else. the weight of the new man is
Algebra.Com
Question 791934: the average of 15 men in a boat is increased by 3 kg when one of the crew who weights 40kg, is replaced by someone else. the weight of the new man is
Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!
the average of 15 men in a boat is increased by 3 kg when one of the crew who weights 40kg, is replaced by someone else.
the weight of the new man is:
:
Let k = the average weight of the 1st 14 guys
Let A = the original average of the 15 guys
then
(A+3) = the average when one guy is replaced
let x = the weight of the new guy.
:
Equation for the original crew
= A
14k + 40 = 15A
:
Equation when one guy is replaced
= A + 3
14k + x = 15(A+3)
14k + x = 15A + 45
14k + x - 45 = 15A
:
15A = 15A so we can write it
14k + x - 45 = 14k + 40
subtract 14k from both side
x - 45 = 40
x = 40 + 45
x = 85 kg, weight of the new guy, a big dude!
RELATED QUESTIONS
the weights of four rowers of a boat respectively 70 kg, 72 kg and 74 kg and the average... (answered by Fombitz)
the average age of 8 men is increased by 2 when two men of 21 yrs and 23 yrs are replaced (answered by ankor@dixie-net.com)
The average age of 8 men is increased by 2 years when two of them whose ages are 21 years (answered by robertb)
the average age of 8 men is increased by 2 years when 2 of them whose ages are 21 years... (answered by Theo)
A boat is to b manned by 8 men,of whom,one cannot row on the bow side and two cannot row... (answered by Edwin McCravy)
The average age of a group of 20 boys is increased by one year when 5 of them whose... (answered by god2012)
The average weight of a group of 10 people increases by 1 kg when one of
them weighing... (answered by ankor@dixie-net.com)
the average of 8 men is increased by 2 years when one of them whose age is 24 years is... (answered by richwmiller)
An eight-oared boat is to be manned by a crew chosen from 11 men of whom 3 can steer but... (answered by Theo)