alleryStart learning →Seven numbers have mean 9. The first four have mean 8 and the last four have mean 11. The fourth number is
A11
B12
C14
D13
Answer & Solution
Correct answer: D. 13
Total is 63, the two groups give 32 plus 44 which is 76, and the overlap is 76 minus 63, which is 13.
Keep practising Data interpretation and analysis
Browse all Data interpretation and analysis questions for Olympiad (Class 7), or explore more Mathematics topics.
Related questions
A pupil scored 76, 82 and 78. What is needed in a fourth test to average 80?A pupil averaged 72 in five tests. What score in a sixth test lifts the mean to 75?In a class of 36, a quarter walk and a third take the bus. The rest cycle. How many cycle?Nine students average 50 marks. The topper's 90 is removed. The mean of the other eight isThe numbers 4, 6, 6, 8 and x have mean 7. Find x.Four ordered numbers have median 9. The larger middle number is 11. The smaller middle numThe mean of six values is 8. Each is tripled and then 2 is subtracted. The new mean isA pin lands point up 30 times in 50 throws. The experimental probability of point up is