Answer:
x=3
Step-by-step explanation:
This is a proportional equation:
Given: x/9=9/27
Cross-multiply: 27x=81
Divide: x=3
So x=3
Answer:
30 grams
Step-by-step explanation:
half life is 60 days so every 60 days the amount 480 grams will be half
in 240 days will decay 240 /60 = 4 times
once 480 /2 = 240
twice 240 /2 = 120
trice 120 / 2 = 60
four times 60/2 = 30 grams will be left
1/10 because one girl out of ten students wears glasses
6. No, the conclusions wrong because 20 out of 50 peoples favourite is drawing which means 20/50 which equals 0.4 times 100 which is 40% not 60%
7. Yes, the conclusion is right because 5/50 is equal to 0.1 times 100 which is 10%