Instead of finding how much each individual animal weighs and then determine the total weight of all three, it is good to find weight of all tree because it is asked in question.
Learn to quickly calculate the total weight of 2 sheep, 2 horses, and 2 frogs, and understand the method to answer the question efficiently.
In first three there are 2sheep+2horse+2frog and their weight=10+20+24
so answer is (1frog+1horse+1sheep) =54/2= 27kg
Brain Teaser Questions 