The ratio of Mariana’s, Vanessa’s,
and David’s ages is eight to six to seven. There is a 10-year age difference
between Mariana and Vanessa. How old is David?
The three parts of the ratio will
be given in the same order as the names have been listed. We know that David’s age
corresponds to seven parts of this ratio. So in order to work out how old
David is, we need to know what one part of the ratio is worth. We are told that there is a 10-year
age difference between Mariana and Vanessa.
The difference between the number
of parts of the ratio that Marianna has and the number that Vanessa has is two,
which means that two parts is equivalent to 10 years. We can find the value of one part
of the ratio by dividing by two. One part is equal to five
To find David’s age, we need to
multiply this by seven. So seven parts of the ratio will be
equal to seven multiplied by five. David is 35 years old.