Which of the following is an iron ore?

The metal which is always present in an amalgam is:

Rock salt is an ore of one of the following metals. This metal is:

1. The number of protons in an atom of an element A is 29 then, the number of electron in its ion A⁺ is:

1. In the given reaction,

Al₂O₃ + NaOH → ……X…… + H₂O

What is element X?

1. Which of the following represent the correct order of decreasing reactivity?

1. The 21st term of the AP whose first two terms are -3 and 4 is

What is the common difference of an AP in which a18 – a14 = 32?

Two APs have the same common difference. The first term of one of these is -1 and that of the other is – 8. Then the difference between their 4th terms is

The famous mathematician associated with finding the sum of the first 100 natural numbers is:

1. Which of the following are the n^th terms of an AP.

Find the 20th term of the AP whose 7th term is 24 less than the 11th term, first term being 12.

If the nth terms of the two APs: 9, 7, 5,… and 24, 21, 18,. .. are the same, find the value of n.

How many numbers lie between 10 and 300, which when divided by 4 leave a remainder 31

The first term of an AP is -5 and the last term is 45. If the sum of the terms of the AP is 120, then find the common difference.

If an = 3 – 4n, . find S20