PSLE
Three boys, Joe, Roy and Sam had the same number of notes. Joe and Roy each had of mix of $10-notes and $5-notes. Joe had 15 $5-notes while Roy had 23 $5-notes. Sam had only $10-notes.

1. Of the three boys, who had the most money? 
2. What was the difference in the total value of Joe and Roy's notes? 
3. Roy used all his $10-notes to buy a gift. He then had $175 less than Sam. How many $10-notes did Sam have?

(a)
The three boys had the same number of notes.
$5-notes have a lower denomination than $10-notes.

Since Sam had only $10-notes, he had the most money.

(b)
Difference in the number of notes of different values
= 23 - 15
= 8

Difference in the value of $10-notes and $5-notes
= 10 - 5
= $5

Difference in the total value of Joe's and Roy's notes
= 8 x 5
= $40

(c)
Value of $5-notes that Roy had left
= 23 x 5
= $115

Total value that Sam had
= 175 + 115
= $290

Number of $10-notes that Sam had
= 290 ÷ 10
= 29

Answer(s): (a) Sam; (b) $40; (c) 29