Unit test math question

1. On mixing two classes A and B of students having average marks 25 and 40 respectively, the overall average obtained is 30. Find the ratio of the students in the class A and B.

2. The ratio of boys and girls in a college is 5 : 3. If 50 boys leave the college and 50 girls join the college, the ratio becomes 9 : 7. The number of boys in the college is?

3. The ratio of the number of boys and girls in a school is 8 : 12. If 50% of boys and 25% of girls are getting scholarships for their studies, what is the percentage of school students who are not getting any scholarships ?

4. The ratio of two numbers is 3 : 8 and their difference is 115. The smaller of the two numbers is ?

5. A milkman makes 20% profit by selling milk mixed with water at 9 per litre . If the cost price of 1 litre pure milk is 10, then the ratio of milk and water in the mixture is

6. The average of the first 7 integers in a series of 13 consecutive odd integers is 37. What is the average of the entire series?

7. The mean of 11 numbers is 35. If the mean of first 6 numbers is 32 and that of the last 6 numbers is 37, find the sixth number.

8. In a 20 over match, the required run rate to win is 7.2. If the run rate is 6 at the end of the 15th over, the required run rate to win the match is ?

9. The average of 100 numbers is 44. The average of these 100 numbers and 4 other new numbers is 50. The average of the four new numbers will be?

10. Out of three numbers, the first is twice the second and is half of the third. If the average of the three numbers is 56, then difference of first and third number is?