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Hi Rapin, Let W = the number of eggs a white hen lays in a day and R = the number of eggs a red hen lays in a day. Then 4W + 3R = the number of eggs laid by 4 white hens and 3 red hens in 15 days. Also, 3W + 5R = the number of eggs 3 white hens and 5 red hens can lay in 12 days. Since you've been told these two totals are the same, then Red hens can lay 20R eggs in twenty days. So you need to know what is 20R/W. Can you solve the last equation for 20R/W? Cheers,  


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