Guest Posted October 28, 2011 Report Share Posted October 28, 2011 The average weight of some monkeys in a bag is doubled when one giant monkey is added to the four monkeys already in the bag. The ratio of the weight of this giant monkey to the total weight of the other four monkeys is 3:? Quote Link to comment Share on other sites More sharing options...
0 Thalia Posted October 28, 2011 Report Share Posted October 28, 2011 3? If the weight doubled when you added the giant monkey, that would mean that in terms of weight, 1 giant monkey= 4 smaller monkeys. Quote Link to comment Share on other sites More sharing options...
0 Guest Posted October 28, 2011 Report Share Posted October 28, 2011 [spoiler=]1 Giant monkey=3 times avg weight so giant monkey:4 monkeys= 3:6 (1:2) Quote Link to comment Share on other sites More sharing options...
0 Guest Posted October 28, 2011 Report Share Posted October 28, 2011 1 giant monkey=5 times avg weight of 3 monkeys so giant monkey : 4 monkeys = 5:8 Quote Link to comment Share on other sites More sharing options...
0 Thalia Posted October 28, 2011 Report Share Posted October 28, 2011 1 giant monkey=5 times avg weight of 3 monkeys so giant monkey : 4 monkeys = 5:8 Oops. Average isn't total weight. If the average weight of 4 monkeys in the bag before the giant monkey goes in is x, (4x+y)/5 monkeys=2x if y is the big monkey. Solving for y gives 6x. So wouldn't it be giant:4 small = 6:4 or 3:2? Quote Link to comment Share on other sites More sharing options...
0 Guest Posted October 28, 2011 Report Share Posted October 28, 2011 I think it is 3 : 2 If x is the total weight of the four monkeys, the average wt. is x/4. If y is the wt. of the big monkey, then the total wt. becomes x+y, and the average becomes (x+y)/5. As new average is double the original, we get, 2 (x/4) = (x+y)/5 On solving, we get, y/x = 3/2 which is what is asked Quote Link to comment Share on other sites More sharing options...
0 Guest Posted October 28, 2011 Report Share Posted October 28, 2011 Thank you! Very intuitive! Quote Link to comment Share on other sites More sharing options...
0 Guest Posted October 28, 2011 Report Share Posted October 28, 2011 @thalia: Hmm i was wrong twice! Quote Link to comment Share on other sites More sharing options...
0 Guest Posted October 29, 2011 Report Share Posted October 29, 2011 is any of the previous answers the right one? Quote Link to comment Share on other sites More sharing options...
0 Guest Posted October 30, 2011 Report Share Posted October 30, 2011 (edited) is any of the previous answers the right one? 2 correct answers so far, post 8 from Thalia & post 9 from SMV Oops. Average isn't total weight. If the average weight of 4 monkeys in the bag before the giant monkey goes in is x, (4x+y)/5 monkeys=2x if y is the big monkey. Solving for y gives 6x. So wouldn't it be giant:4 small = 6:4 or 3:2? I think it is 3 : 2 If x is the total weight of the four monkeys, the average wt. is x/4. If y is the wt. of the big monkey, then the total wt. becomes x+y, and the average becomes (x+y)/5. As new average is double the original, we get, 2 (x/4) = (x+y)/5 On solving, we get, y/x = 3/2 which is what is asked Edited October 30, 2011 by thoughtfulfellow Quote Link to comment Share on other sites More sharing options...
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The average weight of some monkeys in a bag is doubled when one giant monkey is
added to the four monkeys already in the bag. The ratio of the weight of this giant monkey
to the total weight of the other four monkeys is 3:?
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