PSLE
Three men, Rio, Dan and Joe had the same number of notes. Dan and Rio each had of mix of $20-notes and $10-notes. Dan had 11 $10-notes while Rio had 16 $10-notes. Joe had only $20-notes.

1. Of the three men, who had the least money? 
2. What was the difference in the total value of Dan and Rio's notes? 
3. Rio used all his $20-notes to buy a gift. Joe then had $280 more than Rio. How many $20-notes did Joe have?

(a)
The three men had the same number of notes.
$10-notes have a lower denomination than $20-notes.

Rio had more $10-notes than Dan while Joe had only the $20-notes.  

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

(b)
Difference in the number of notes of different values
= 16 - 11
= 5

Difference in the value of $20-note and $10-note
= 20 - 10
= $10

Difference in the total value of Dan's and Rio's notes
= 5 x 10
= $50

(c)
Value of $10-notes that Rio had left
= 16 x 10
= $160

Total value that Joe had
= 280 + 160
= $440

Number of $20-notes that Joe had
= 440 ÷ 20
= 22

Answer(s): (a) Rio; (b) $50; (c) 22