Answer :
x=biscuit
x+15p (cake)
x+15p+2x=90p
3x+15p=90p
3x=90p-15p
3x=75p
x=75p÷3
x=25p
biscuit= 25p
cake= 25p+15p =40p
x+15p (cake)
x+15p+2x=90p
3x+15p=90p
3x=90p-15p
3x=75p
x=75p÷3
x=25p
biscuit= 25p
cake= 25p+15p =40p