The hydronium ion is H₃O⁺ and its concentration is equivalent to the H⁺ ion concentration. The H⁺ ion concentration is given by:
pH = -log[H⁺]
[H⁺] = 10^(-8.2)
[H⁺] = 6.31 x 10⁻⁹ mole/dm³
The hydronium ion concentration is 6.31 x 10⁻⁹ mole/dm³
First,you do,2/5+2/3,but since you will need a common denominator,you will find the least common denominator for 5 and 3.The LCD(Least Common Denominator) will be 15 since both 5 and 3 could go in 15.Now,the equation looks like this: 2/15+2/15 since whatever you do to the bottom numbers,you NEED to do to the top numbers:2 and 2.Now you will need to do,2x3,since 5x3=15 and the answer to 2x3=6 then you do 2x5,since 3x5=15 the answer is 10 now the equation looks like this:6/15+10/15 now you add them together,and the answer will be 16/15 and if you want the answer to be a mixed number,it would look like this: 1 1/15. Hope this helps!
Let the price of adult ticket and children ticket be a and c respectively
8a+5c=177.50 -> 24a+15c=532.5
12a+6c=255.00 -> 24a+12c=510
24a+15c-24a-12c=532.5-510
3c=22.5
c=7.5
a=17.5