1. which term is -81 in the A.P:- 21,18,15,..................
A) 31st B) 35th C) 34th D) 37th
2. The number of rows is there in the flower bed if 23 rose plants in the 1st row, 21 in the second row, 19 in the 3rd and so on there are 5 5 rose plants in the last row.
A) 9 B) 10 C) 8 D) 11
Answers
Answered by
1
an=-81
a+(n-1)d= -81
21+(n-1)(-3)= -81
21-3n+3= -81
24-3n= -81
-3n= -81-24=-105
n= -105/-3=35
ans is option b
2)
an=a+(n-1)d
5=23+(n-1)-2
5=23+2-2n
-2n=5-25=-20
n=10
a+(n-1)d= -81
21+(n-1)(-3)= -81
21-3n+3= -81
24-3n= -81
-3n= -81-24=-105
n= -105/-3=35
ans is option b
2)
an=a+(n-1)d
5=23+(n-1)-2
5=23+2-2n
-2n=5-25=-20
n=10
Akhilkumar01:
Thanks
Answered by
1
hii dear here is your answer.........
1). An=-81
◆a1=21
◆d=18-21=-3
◆An=a+(n-1)d
◆-81=21+(n-1)-3
◆]-81-21=(n-1)-3
◆-102=(n-1)-3
◆-102/-3=(n-1)
◆34=(n-1)
◆n=35th term is -81
2)a=23
d=21-23=-2
An=55
An=a+(n-1)d
5=23+(n-1)-2
5-23=(n-1)-2
-18/-2=(n-1)
9=(n-1)
n=10
so B is correct
hope it helps you☺️☺️☺️
1). An=-81
◆a1=21
◆d=18-21=-3
◆An=a+(n-1)d
◆-81=21+(n-1)-3
◆]-81-21=(n-1)-3
◆-102=(n-1)-3
◆-102/-3=(n-1)
◆34=(n-1)
◆n=35th term is -81
2)a=23
d=21-23=-2
An=55
An=a+(n-1)d
5=23+(n-1)-2
5-23=(n-1)-2
-18/-2=(n-1)
9=(n-1)
n=10
so B is correct
hope it helps you☺️☺️☺️
Similar questions
Computer Science,
8 months ago
Math,
8 months ago
Math,
1 year ago
Math,
1 year ago
Chemistry,
1 year ago