You have 105 cowry shells. If a dozen eggs cost 10 cowry shells, how many eggs can you purchase?

2 Answers
Mar 23, 2018

#126# eggs

Explanation:

As a dozen i.e. #12# eggs cost #10# cowry shells,

each cowry shell can buy #12/10# eggs

and #105# cowry shells can buy #12/10xx105# eggs

= #12/(cancel10^2)xxcancel105^21# eggs #-#dividing by #5#

= #(cancel12^6)/(cancel2^1)xx21# eggs #-#dividing by #2#

= #6xx21=126# eggs

If we can only buy eggs by the dozen, then we end up with #120" eggs" and 5 " cowry shells"#

Explanation:

An alternate way of looking at this problem is to ask if we can only buy eggs by the dozen. If so, then we can buy 10 sets of a dozen eggs each and have 5 cowry shells left over. This gives:

#10xx12=120" eggs" and 5 " cowry shells"#