your first constant of propotionality is 10
The second constant of propotionality 5

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So, we have the following equation...

Remember
and
is the following...

Therefore, 
So, your final answer is
.
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<em>Glad to help!</em>

<span>Let x be
additional food item the homeroom B should collect to have greater item per student than
homeroom A.</span>
(22 +24 + x) /
16 > (30 + 42 + 21) /24
(22 +24 + x)
> 3.875 (16)
X > 16
<span>So they should
collect more than 16 food item to have a greater item per student</span>
Annual growth rate is (1+0.15)^12. or 5.35025 or 535.025%