Question 13
Khánh puts one banknote into a piggy bank on each of 10 occasions. The possible denominations are 1, 2, 5, 10 and 20 thousand đồng, and every denomination is used at least once. A 5-thousand-đồng note is used on exactly 3 occasions. The 10-thousand-đồng note is used more often than each other denomination. How much does Khánh deposit in total, in thousands of đồng?
