Help Me SmartCookieZ

You don't have to ask for one person specifically. Other people can help too, unless this is a problem you specifically want him/her to answer because of something.

Hey Guest! 

Thank you for asking me specifically but as sparkling water said, you don't need to ask for a certain person. 

I'm not quite sure how to approach this problem but this is my best attempt: so each cupcake costs twice as much as a sardine pie, therefore c=2s (c represents cupcake and s represents sardine pie) so the cost of 2 cupcakes and 8 sardine pies is the same as the cost of 12 sardine pies. She then spent 3/4 of her remaining money which is 3/4 of the 4/7 left. This amount is the same as 1/7 of the original amount. The question says that pandan cakes cost 4.50 more than cupcakes but gives no clue as to the other prices. This leaves me at a dead end. You could instead change to amount of sardine pies into cupcakes so the cost of 2 cupcakes and 8 sardine pies is the same as the cost of 6 cupcakes but this still doesn't help us. 

Could someone else try this question? I am new to this website and I do not have a great knowledge of maths so someone else here might be able to help.

SCZ

To determine the amount Jean spent all together, we have to determine the cost of each of cupcakes sardine pies and pandan cakes. For this let S be the total money Jean have with her and let x be  the price of a sardine pies and . 

It is given that each cupcake cost twice as much as a sardine pie. Therefore cost of a cup cake will be 

2x. And it is also given that each pandan cake cost $4.50 more than a cupcake. Therefore the cost of a pandan cake will be 4.5+2x.

Now Jean spends 3/7^_th her money buying 2 cupcakes and 8 sardine pies. which can be represented as an equation as follows;

   3S/7 = 2(2x) + 8x

           = 4x + 8x

           = 12x

∴ 3S/7 = 12x ⋯⋯⋯⋯⋯ (1)

Now the remaining amount left with her will be;

S - 3S/7 = 7S - 3S/7

              = 4S/7

Now spends 3/4^th of this remaining money on 3 pandan cakes which can be represented as an equation as follows;

3/4 ⋅ 4S/7 = 3(2x + 4.5) 

        3S/7 = 6x + 13.5 ⋯⋯⋯⋯⋯ (2) 

Now right hand side of both equation (1) and (2) are the same. So equating the right hand side of the two equations and solving for x as follows;

      12x=6x + 13.5

12x - 6x=13.5

         6x=13.5

           x=13⋅5/6

             =2.25

Therefore the cost of a sardine pies is $2.25 
Therefore the cost of a cup cake is equal to;

2x=2⋅2.25

    =$4.5

And the cost of Pandan pie is equal to;
2x + 4.5=4.5 + 4.5

             =$9

Therefore the total amount spend in buying 2 cupcakes 8 sardine pies, and 3 Pandan cake is given by;

total amount = 2(2x) + 8x + 3(2x + 4.5)

                     = 2 ⋅ 4.5 + 8 ⋅ 2.25 + 3 ⋅ 9

                     = 54

Therefore the total amount she have spend is $54.