EASY
JEE Main
IMPORTANT
Earn 100

If the 10th term of an A.P. is 120 and its 20th term is 110, then the sum of its first 200 terms is

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Important Questions on Sequences and Series

EASY
JEE Main
IMPORTANT
The product 214·4116·8148·161128·.... to is equal to:
HARD
JEE Main
IMPORTANT
Let an be the nth term of a G.P. of positive terms. If n=1100a2n+1=200 and n=1100a2n=100, then n=1200an is equal to:
MEDIUM
JEE Main
IMPORTANT
If x=n=0-1ntan2nθ and y=n=0cos2nθ, for 0<θ<π4, then:
MEDIUM
JEE Main
IMPORTANT
The number of terms common to the two A.P.’s 3,7,11,,407 and 2,9,16,,709 is ____________.
MEDIUM
JEE Main
IMPORTANT
Let the sum of the first n terms of a non-constant A.P., a1, a2, a3, ...., an be 50n+n(n-7)2A, where A is a constant. If d is the common difference of this A.P., then the ordered pair d, a50 is equal to
MEDIUM
JEE Main
IMPORTANT
The sum of the series 1+2×3+3×5+4×7+ upto 11th term is:
MEDIUM
JEE Main
IMPORTANT
Some identical balls are arranged in rows to form an equilateral triangle. The first row consists of one ball, the second row consists of two balls and so on. If 99 more identical balls are added to the total number of balls used in forming the equilateral triangle, then all these balls can be arranged in a square, whose each side contains exactly 2 balls less than the number of balls each side of the triangle contains. Then the number of balls used to form the equilateral triangle is