Hilda baked 154 cupcakes and cookies. She burnt 4 pieces and counted the remaining pieces. ¹₄ of the cookies and ⁶₇ of the cupcakes were banana flavoured. There were equal number of cookies and cupcakes that were chocolate chip flavoured.

1. How many unburnt chocolate chip cupcakes were there?
2. What fraction of the unburnt pastries were banana cupcakes?

(a)
Number of pastries that was not burnt
= 154 - 4
= 150

Fraction of the cookies that was chocolate chip flavoured
= 1 - ¹₄ 
= ³₄ 

Fraction of the cupcakes that was chocolate chip flavoured
= 1 - ⁶₇ 
= ¹₇ 

The number of chocolate chip cookies and chocolate chip cupcakes was the same. Make the numerators the same. 
34 Cookies = 1x37x3 Cupcakes 
34 Cookies = 321 Cupcakes 

Number of unburnt cookies = 4 u
Number of unburnt cupcakes = 21 u

Total number of unburnt pastries
= 4 u + 21 u
= 25 u

25 u = 150

1 u = 150 ÷ 25 = 6

Number of unburnt chocolate chip cupcakes
= 3 u
= 3 x 6
= 18

(b)
Number of unburnt banana cupcakes
= 21 u - 3 u
= 18 u

^{Unburnt banana cupcakes}_{Total unburnt pastries}
= ¹⁸_{4 + 21}
= ¹⁸₂₅

Answer(s): (a) 18; (b) ¹⁸₂₅