A frog lays 800 eggs a year.  10 percent dry up, and 70 percent are eaten.  1/4 of the remaining eggs end up hatching, how many frogs hatch out of the 800?
How many eggs dry up? ** Dried up:800(.10)=80 eggs
How many eggs are eaten? ** 800(.70)=560 eggs
How many eggs are left? ** Total left:800-80-560=<<800-80-560=160>>160 eggs
How many eggs end up hatching? ** 160/4=<<160/4=40>>40 eggs survive to hatch
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