PSLE
Three men, Don, Joe and Eli had the same number of notes. Joe and Don each had of mix of $100-notes and $10-notes. Joe had 8 $10-notes while Don had 18 $10-notes. Eli had only $100-notes.

1. Of the three men, who had the least money? 
2. What was the difference in the total value of Joe and Don's notes? 
3. Don used all his $100-notes to buy a present. Eli then had $2120 more than Don. How many $100-notes did Eli have?

(a)
The three men had the same number of notes.
$10-notes have a lower denomination than $100-notes.

Don had more $10-notes than Joe while Eli had only the $100-notes.  

Since Don had the most number of $10-notes, he had the least money.

(b)
Difference in the number of notes of different values
= 18 - 8
= 10

Difference in the value of $100-note and $10-note
= 100 - 10
= $90

Difference in the total value of Joe's and Don's notes
= 10 x 90
= $900

(c)
Value of $10-notes that Don had left
= 18 x 10
= $180

Total value that Eli had
= 2120 + 180
= $2300

Number of $100-notes that Eli had
= 2300 ÷ 100
= 23

Answer(s): (a) Don; (b) $900; (c) 23