The answer would be mercury.
If we know that 30% of the time is used after 9 minutes we can write this mathematically as:

By solving for x we can determine the total time allowed to play games and so:

The total time allowed to play games is 30 minutes. Since 9 minutes have lapsed 30-9=21 minutes left to play.
You multiply and add like terms, depending on the equation that you have
Its 2. because yea you know whats going on
Answer:
a) 81-6
b) 10.4
Step-by-step explanation:
a) assuming that the VAT is 20% of the 68 pounds,
you calculate 120% of 68 (convert percentage to decimal)
= 1,20 * 68 = 81.6 pounds
or
calculate 20% of 68 pounds and add the answer to 68 pounds:
(0.2 * 68) + 68 = 81.6 pounds
b) 20% of 52
first convert the percentage to decimals:
0.2 * 52 = 10.4 pounds