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?
A cricketer has a certain average for 9 innings. In the tenth innings, the score is 100 runs, thereby increasing his average by 8 runs. His new average is:
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