Ken spends 1/5 of his money on a dictionary. He gives $21 to his brother and has1/2 of his money left. How much money does Ken have left?

Ken has 1 of his money. He spends 1/5 so he still has 4/5 of the original amount of money. He has 4/5 and he spends $21and ends up with 1/2 of his money. 4/5 = 8/10 and 1/2 = 5/10. This means that $21 is 8/10-5/10 of his original amount of money. so $21 is 3/10 of his original amount of money. 21/3*10=70. His original amount of money is $70. This means that 1/2 of his money is $35. So Ken has $35 left.