The number of boys in a class is three times the number of girls. Which one of the following numbers cannot represent the total number of children in the class?

There are some ducks and goats in a ground. Total no of heads and feet are 77 and 224 respectively. How many ducks are there in the ground?

If all the numbers from 501 to 700 are written, what is the total number of times does the digit 6 appear?

John's age is 42 years and Kelvin's age is 26 years. How many years ago was Kelvin's age half of John’s age?

Some oranges were distributed among 40 children equally. If 20 more children were there, each child would have got 5 less oranges. How many oranges are there at the beginning?

A book has 300 pages and each page has 20 lines of 10–10 words. Find the no. of words in the book.

In an exam, a student gets 4 marks for each correct answer, but loses one for a wrong answer. There were 60 questions and he got 130 marks. Find the number of correct answers.

Pointing to a photograph, a lady tells Pramod, “I am the only daughter of this woman and her son is your maternal uncle.” How is the speaker related to Pramod’s father?

Pointing to a person, a man said to a woman, “His mother is the only daughter of your father.” How is the woman related to the person?