The average age of a man and his two twin born on the same day is $30 \,year.$ The ratio of the ages of father and one son is $5: 2,$ what is the father's age in $year?$
$50$
$30$
$45$
$20$
The total marks obtained by a student in Physics, Chemistry and Mathematics together is $120$ more than the marks obtained by him in Chemistry. What is the average marks obtained by him in Physics and Mathematics together ?
The average of $25$ consecutive odd integers is $55 .$ The highest of these integers is
The average of three numbers is $135 .$ The largest number is $195$ and the diference between the other two is $20 .$ The smallest number is
The average of three consecutive odd numbers is $12$ more than one-third of the first of these numbers. What is the last of the three numbers ?
The sum of the ages of father and son at present is $33\,years.$ Two years ago the product of their ages was $28 \,years.$ What is the age of the father and the son? (in $years$)