PSLE
Three men, Ned, Bo and Joe had the same number of notes. Bo and Ned each had of mix of $20-notes and $10-notes. Bo had 2 $10-notes while Ned had 15 $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 Bo and Ned's notes? 
3. Ned used all his $20-notes to buy a present. Joe then had $450 more than Ned. 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.

Ned had more $10-notes than Bo while Joe had only the $20-notes.  

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

(b)
Difference in the number of notes of different values
= 15 - 2
= 13

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

Difference in the total value of Bo's and Ned's notes
= 13 x 10
= $130

(c)
Value of $10-notes that Ned had left
= 15 x 10
= $150

Total value that Joe had
= 450 + 150
= $600

Number of $20-notes that Joe had
= 600 ÷ 20
= 30

Answer(s): (a) Ned; (b) $130; (c) 30