Series Arithmetic

A gardener plans to construct a trapezoidal shaped structure in his garden. The longer side of trapezoid needs to start with a row of 97 bricks. Each row must be decreased by 2 bricks on each end  and the construction should stop at 25^th row. How many bricks does he need to buy ?

Find the sum of the 1st 20 terms: 2+5+8+......

• 1220

• 610

• 600

• 612

The next two terms of the sequence 4,7,10,13 are ....

• 16 and 19

• 15 and 19

• 16 and 18

• 15 and 18

Find the sum of the 1st 100 terms: 100+98+96+......

• 100

• 1000

• 50

• -98

Find the sum: 50 + 48 + 46 + ..... + 10

• 630

• 21

• 210

• 1260

Find S₁₄ 
7, 2, -3, ...

• -812

• 119

• -945

• -357

Find the 22nd term of the following sequence:
5, 8, 11, ...

• 14

• 68

• 63

• 71

Find the first term of the given sequence:
a₁₄=68
d=3

• 14

• 20

• 26

• 29

Identify the common difference.
97, 86, 75, 64, ...

• 8

• 11

• -11

• -8

Is the sequence arithmetic: 17, 9, 1, -7, ...

• Yes

• No