If the mean of a,b,c is M and ab + bc + ca = 0, then the mean of a2, b2, c2 is
Three years ago, the average age of X, Y and Z was 27 years and that of Y and Z, 5 years ago was 20 years. X’s present age is:
3 person A, B and C covers a distance at 10 km/hr ,12 km/hr and 15 km/hr. the average speed is:
A person starting from his house covers a distance at 15 km/hr and returns to the starting place at 10 km/hr. His average speed during whole journey is
The mean temperature of Monday to Wednesday was 37C and of Tuesday to Thursday was 34C. If the temperature on Thursday was 4/5 that of Monday, the temperature on Thursday
A man whose bowling average is 12.4 takes 5 wickets for 26 runs and thereby decreases his average by 0.4. The number of wickets, taken by him before his last match is:
A man takes 5 hours to walk to a certain place and returns by car. He would have, however, gained 3 hours if he had completed his entire journey by car. How long would he have taken to walk both ways?
The average age of a committee of eight members is 40 years. A member aged 55 years retired and his place was taken by another member aged 39 years. The average age of the present committee is:
The average weight of 6 men decreases by 3 kg when one of them weighing 80 kg is replaced by a new man. The weight of the new man is:
The average weight of 8 men is increased by 1.5 kg when one of the men who weighs 65 kg is replaced by a new man. The weight of the new man is:
The average age of 40 students of a class is 15 years. When 10 new students are admitted, the average is increased by 0.2 years. The average age of new students is:
The average age of 30 students is 9 years. If the age of their teacher is included, it becomes 10 years. The age of the teacher (in years) is:
The average of six numbers is 30. If the average of first four is 25 and that of last three is 35, the fourth number is:
The mean of 100 observations was calculated as 40. It was found later on that one of the observations was misread as 83 instead of 53. The correct mean is:
The average of ten numbers is 7. If each number is multiplied by 12, then the average of new set of numbers is:
Of three numbers, second is twice the first and is also thrice the third. If the average of the three numbers is 44, the largest number is:
The average price of three items of furniture is Rs. 15000. If their prices are in the ratio 3:5:7, the price of the cheapest item is:
On Children Day, sweets were to be equally distributed among 175 children in a school. Actually on the Children’s Day, 35 children were absent and therefore each child got 4 sweets extra. Total how many sweets were available for distribution?
None of these
A classroom has equal number of boys and girls. Eight girls left to play Kho-Kho, leaving twice as many boys as girls in the classroom. What was the total number of girls and boys present initially?
None of these
The average of eight numbers is 14.. The average of six of these numbers is 16. The average of the remaining two numbers is: