The average of 15 numbers is 18. The average of first 8 is 19 and that last 8 is 17, then the 8th number is
A
15
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
16
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
18
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
20
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution
The correct option is C18 Average =SumofnumbersNo.ofnumbers 18=Sumofnumbers15 Sum of numbers =18×15=270 Average of first 8 numbers =Sumoffirst8numbers8 sum of first 8 nos. =19×8=152 Average of last 8 nos. =Sumoflast8nos.8 Sum of last 8 nos. =17×8=136 Eight number = Sum of first 8 nos. + sum of last 8 nos. - sum of 15 nos. =152+136−270=288−270 =18