Question : What is the sum of the first 9 terms of an arithmetic progression, if the first term is 7 and the last term is 55?

Option 1: 219

Option 2: 137

Option 3: 231

Option 4: 279

Question : The sum of the first 20 term of the series $\frac{1}{5×6}+\frac{1}{6×7}+\frac{1}{7×8}+....$ is:

Option 1: 0.16

Option 2: 1.6

Option 3: 16

Option 4: 0.016

Question : Find the value of the given expression:
$10 \div 5 × 1+3 - [8 - \{5 - (7 - 7 - 9)\}]$

Option 1: 11

Option 2: 10

Option 3: 9

Option 4: 8

Question : The arithmetic mean of the following numbers
1, 2, 2, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7 is:

Option 1: 4

Option 2: 5

Option 3: 14

Option 4: 20

Question : What is the sum of the first 20 terms of the following series?
$1 \times 2+2 \times 3+3 \times 4+4 \times 5+\ldots \ldots$

Option 1: 3160

Option 2: 2940

Option 3: 3240

Option 4: 3080