Sequences and series

The 10th term of the AP 3, 7, 11, ... is:

• 1 37
• 2 40
• 3 43
• 4 39

The sum of the first 10 natural numbers is:

• 1 45
• 2 55
• 3 100
• 4 50

The 5th term of the GP 2, 6, 18, ... is:

• 1 486
• 2 162
• 3 54
• 4 81

The sum to infinity of the GP 1 + 1/2 + 1/4 + ... is:

• 1 1
• 2 2
• 3 3
• 4 Infinite

The harmonic mean of 2 and 6 is:

• 1 4.5
• 2 3.5
• 3 3
• 4 4

The sum of the first n terms of an AP is:

• 1 n/2 (2a + (n - 1)d)
• 2 n a d
• 3 a + nd
• 4 n/2 (a + d)

The common ratio of the GP 4, 8, 16 is:

• 1 12
• 2 4
• 3 2
• 4 1/2

The arithmetic mean of 10 and 20 is:

• 1 200
• 2 15
• 3 30
• 4 10