posted by TommyBoy on .
A farmer had 500 ducks and 300 chickens. He gave his sister 100 chickens and ducks. Later, the farmer bought 10 more ducks and 75 more chickens. As a result, the number of ducks decreased by 12% and the number of chickens increased by 15%.
a) How many ducks did the farmer give away?
b) How many chickens did he give away?
We can do this without algebra:
originally he had 500 ducks
the final number was 12% less , or 88% of the original
= 440 ducks
but that includes the purchase of 10 ducks, so the give-away must have been 70 ducks
so he must have given away 30 chickens
so his final count for chickens
= 300 - 30 + 75 (the new purchase) = 345
change = increase of 45 chickens
is this 15% of 300 ? YES
He gave his sister 70 ducks and 30 chickens
Explain ur answers more