wiz-icon
MyQuestionIcon
MyQuestionIcon
3
You visited us 3 times! Enjoying our articles? Unlock Full Access!
Question

The first and the last terms of an AP are 17 and 350 respectively. If the common difference is 9, then find the number of terms in the AP and their sum.


A

32; 6973

No worries! We‘ve got your back. Try BYJU‘S free classes today!
B

38; 6973

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C

32; 7114

No worries! We‘ve got your back. Try BYJU‘S free classes today!
D

38; 7114

No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is B

38; 6973


Given,
First term =a=17

Last term =l=350

Common difference =d=9

Using formula an=a+(n1)d, we can say that

350=17+(n1)(9)

350=17+9n9

342=9n

n=3429=38

Applying formula, Sn=n2(2a+(n1)d), we get

S38=382(34+(381)9)

S38=19(34+333)=6973

Therefore, there are 38 terms and their sum is equal to 6973.


flag
Suggest Corrections
thumbs-up
7
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Formula for Sum of N Terms of an AP
MATHEMATICS
Watch in App
Join BYJU'S Learning Program
CrossIcon