Hey Ivy,

Following pls find my worked solution:

<Before>

T : P

4 : 7

<Process>

T gave 2/3 of her cupcakes to P; thereby (1/3) of T's cupcakes remain.

T left: (1/3)x4u = (4/3)u

P left: 7u + [(2/3)x4u] = 7u + (8/3)u = (29/3)u

<After>

T : P

**4 : 29**

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You can also derive the same answer using the standard Model method, in which you multiply the <Before> ratio / model by 3 times.

Then calculate the number of units given by T to P (i.e. (2/3) of 12u = 8u).

Hence, T would be left with (12u - 8u) = 4u ; while P would be increased to (21u + 8u) = 29u.

Ratio T : P (after) = **4 : 29**

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Do let me know again if there's further clarification.

Cheers,

Edward