First, recognise that this a "Total unchanged" problem.

(ie. The "giving" is mutual. Hence the total before and after the giving should remain the same!!)

C D

1u : 8u --> notice total is 9u

+35 -35

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2u : 1u --> notice total is only 3, which is different from beginning

Transform into 9u by multiplying by multiplying by 3:

6u : 3u

Comparing before and after the giving,

5u --> 35

1u --> 35/5 = 7

Crystal (at the end) --> 7 x 6 =

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