Let's let the weight of a large box be L, and the weight of a small box be S.
We know that 5 large boxes and 3 small boxes is 120kg, so:
5L + 3S = 120
We also know that 7 large boxes and 9 small boxes is 234kg, so:
7L + 9S = 234
You can multiply the first equation by 3 to get:
15L + 9S = 360
See how now both equations have 9S? We can now subtract one from the other:
(15L+9S) - (7L+9S) = 360-234
8L = 126
L = 15.75
Now sub this value back into an equation:
(5x15.75) + 3S = 120
3S = 41.25
S = 13.75
Double check these values
(7x15.75) + (9x13.75)
= 110.25 + 123.75
=234, which is consistent with above.
So a large box is 15.75kg, and a small box is 13.75kg.
Hope this helped
Answer:
c
Step-by-step explanation:
Answer: 163 pounds
Step-by-step explanation: 12 stones is 168 pounds
Null hypothesis: 
Alternative hypothesis: 
The null is based on a recent study that 81% of the population (in this case senior citizens) takes at least one medication. The alternative hypothesis is basically the flip of the claim made in the null.
If Amelia wanted to know if the percentage was less than 81%, then the alternative would be p < 0.81
If Amelia wanted to know if the percentage was larger than 81%, then the alternative would be p > 0.81
However, she wants to know if the percentage is 81%.
