Answer:
27
Step-by-step explanation:
If Fiona's age is x, Dan and Gavyn's ages respectively are x + 8 and x - 9. We can write:
x + x + 8 + x - 9 = 56
3x - 1 = 56
3x = 57
x = 19
The eldest is Dan (because x + 8 > x and x + 8 > x - 9). His age is x + 8 = 19 + 8 = 27.
Answer: Three quarters (30 ml) is made up of a 36% acid solution.
Step-by-step explanation:
Since we have given that
Total amount of solution = 40 ml
One- quarter of the solution is given by

Three-quarter of the solution is given by

According to question, we have
10 ml of solution is made up of = 20% of acid solution
30 ml of solution is made up of = say<em> 'c </em>' of acid solution
40 ml of solution is made up of = 32 % of acid solution
So, our equation becomes,

Hence, three quarters (30 ml) is made up of a 36% acid solution.
Answer:
Step-by-step explanation:
the answer is 7.9