R-SAT
Exam
Numerical Ability
Averages
The average of 9 items is 89. If one new item whose value is 69 is also included in the series . Find the average of all the 10 items?
option
A. 83
B. 85
C. 91
D. 87
E. none
Read Solution (Total 10)
-
- D -87
x/9 = 89
sum of 9 items x=801
new avg = (801+69)/10 = 87 - 11 years agoHelpfull: Yes(3) No(0)
- sum=89*9=801
then add 69
so 801+69=870
new avg=870/10=87 - 11 years agoHelpfull: Yes(2) No(0)
- (9*89+69)/10= 87
- 11 years agoHelpfull: Yes(0) No(0)
- x/9=89
x=801
801+69/10=87 - 11 years agoHelpfull: Yes(0) No(0)
- Ans: D
SO 9*89=801
801+69=870
870/10=87. - 11 years agoHelpfull: Yes(0) No(0)
- total cost= 9*89=801
total of 10 items=801+69=870
870/10=87
option E none - 10 years agoHelpfull: Yes(0) No(0)
- AVERAGE OF 9 ITEMS = 89
SO, AVG=SUM OF ALL ITEM VALUES/NUMBER OF ITEMS.
SO,SUM OF ALL ITEM VALUES= NUMBER OF ITEMS * AVG
= 9 * 89
= 801.
if u add one more item with value 69.
the total number of items becomes 9+1=10, and
sum of all 10 item values = 801 + 69 = 870.
now the avg of 10 item is= 870/10
= 87(ans D) - 10 years agoHelpfull: Yes(0) No(0)
- The option D is the correct answer Because avg. of 9 items is 89 so 9*89=801 and one extra item is added then 801+69=870 so total avg is 870/10=87.
- 10 years agoHelpfull: Yes(0) No(0)
- ans d)87
total value of 9 item=9*89=801
value of 1 item=69
total value of 10 item =870
avg=870/10=87 - 9 years agoHelpfull: Yes(0) No(0)
- average=sum of numbers/total number,
89=sum of numbers/9=>sum of numbers=801
69 is included in in the series so 801+69/10 gives avg
ans 87 - 9 years agoHelpfull: Yes(0) No(0)
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