PSLE
Three boys, Lee, Tom and Don had the same number of notes. Lee and Tom each had of mix of $20-notes and $5-notes. Lee had 9 $5-notes while Tom had 14 $5-notes. Don had only $20-notes.

1. Of the three boys, who had the most money? 
2. What was the difference in the total value of Lee and Tom's notes? 
3. Tom used all his $20-notes to buy a gift. He then had $330 less than Don. How many $20-notes did Don have?

(a)
The three boys had the same number of notes.
$5-notes have a lower denomination than $20-notes.

Since Don had only $20-notes, he had the most money.

(b)
Difference in the number of notes of different values
= 14 - 9
= 5

Difference in the value of $20-notes and $5-notes
= 20 - 5
= $15

Difference in the total value of Lee's and Tom's notes
= 5 x 15
= $75

(c)
Value of $5-notes that Tom had left
= 14 x 5
= $70

Total value that Don had
= 330 + 70
= $400

Number of $20-notes that Don had
= 400 ÷ 20
= 20

Answer(s): (a) Don; (b) $75; (c) 20