Quantitative Aptitude - Arithmetic Ability Questions

In the following question, select the odd word pair from the given alternatives

What is the sum of all natural numbers between 100 and 400 which are divisible by 13?

Which of the following is a reductible fraction?

X does 25% of a work in 20 days. Y joins X and they together finish the remaining work in 15 days. Y alone can do the whole work in ___ days.

Three years ago, the average age of a family of 5 members was 17 years. A baby having been born, the average age of the family is the same today. The present age of the baby is

When a discount of 25% is given on a box of popcorn, the profit is 25%. If the discount is 10%, then the profit is

In a cricket match, the scores of the players are considered such that coefficient of variation of scores is 16 and mean is 25 then the variance is

A sum of money becomes 77/50 of itself in 18/5 years when invested at simple interest. What is the rate (in percentage) of interest per annum?