PSLE
Three men, Bo, Ace and Nat had the same number of notes. Ace and Bo each had of mix of $50-notes and $20-notes. Ace had 3 $20-notes while Bo had 20 $20-notes. Nat had only $50-notes.

1. Of the three men, who had the least money? 
2. What was the difference in the total value of Ace and Bo's notes? 
3. Bo used all his $50-notes to buy a present. Nat then had $850 more than Bo. How many $50-notes did Nat have?

(a)
The three men had the same number of notes.
$20-notes have a lower denomination than $50-notes.

Bo had more $20-notes than Ace while Nat had only the $50-notes.  

Since Bo had the most number of $20-notes, he had the least money.

(b)
Difference in the number of notes of different values
= 20 - 3
= 17

Difference in the value of $50-note and $20-note
= 50 - 20
= $30

Difference in the total value of Ace's and Bo's notes
= 17 x 30
= $510

(c)
Value of $20-notes that Bo had left
= 20 x 20
= $400

Total value that Nat had
= 850 + 400
= $1250

Number of $50-notes that Nat had
= 1250 ÷ 50
= 25

Answer(s): (a) Bo; (b) $510; (c) 25