A sports shop had 500 squash balls for sale. Each squash ball is sold at $5. At the end of each day, the number of squash balls sold was recorded in the bar graph shown.

1. What fraction of the total number of squash balls was left at the end of Day 3? Express your answer in its simplest form.
2. If the shop decided to sell every 3 squash balls at $13 from Day 4 onwards, how much less would it collect from the sale of the squash balls?

(a)
Number of squash balls left at the end of Day 3
= 500 - 54 - 54 - 60
= 332

Fraction of squash balls left at the end of Day 3
= ³³²₅₀₀
= ⁸³₁₂₅

(b)
Number of squash balls sold from Day 4 to Day 6
= 36 + 33 + 57
= 126

Amount that it would collect if it sold the 126 squash balls at the original price
= 126 x 5
= $630

Number of sets of 3 squash balls
= 126 ÷ 3
= 42

Amount that it would collect if it sold the 126 squash balls at every 3 squash balls at $13
= 42 x 13
= $546

Amount that it would collect less  from the sale of the squash balls
= 630 - 546
= $84

Answer(s): (a) ⁸³₁₂₅; (b) $84