Irene baked 8 trays of shortbreads. There were 20 shortbreads in each tray. She gave ¹₈ of the shortbreads to her colleagues and ¹₂ of the remainder to Elijah. She then packed the rest of the shortbreads equally into 5 boxes. How many shortbreads were there in each box?
Total number of shortbreads that Irene baked
= 8 x 20
= 160

Fraction of the shortbreads left after Irene gave to her colleagues
= 1 - ¹₈ 
=  ⁷₈ 

Number of shortbreads left after Irene gave to Elijah
= ⁷₈ x 160
= 140 

Fraction of the remaining shortbreads left after Irene gave to Elijah
= 1 - ¹₂ 
=  ¹₂ 

Number of shortbreads that Irene packed into 5 boxes
= ¹₂ x 140
= 70

Number of shortbreads in each box
= 70 ÷ 5
= 14

Answer(s): 14