The document Important Formulae: Progressions CAT Notes | EduRev is a part of the Quant Course Quantitative Aptitude (Quant).

All you need of Quant at this link: Quant

a_{n} = a_{1} + (n - 1)d**EduRev's Tip:**

- Number of terms =

Geometric Progression

a_{n}= ar^{n - 1}

Sum till infinite terms = (Valid only when r<1)

Sum of first n natural numbers

⇒ 1 + 2 + 3 … + n =

Sum of squares of first n natural numbers

⇒ 1^{2}+ 2^{2}+ 3^{2}+ … + n^{2}=

Sum of cubes of first n natural numbers⇒ 1

^{3}+ 2^{3}+ 3^{3}... + n^{3}= Sum of first n odd numbers

⇒ 1 + 3 + 5 … + (2n - 1) = n^{2}Sum of first n even numbers

⇒ 2 + 4 + 6 ... 2n = n(n - 1)If you have to consider 3 terms in an AP, consider {a-d,a,a+d}. If you have to consider 4 terms, consider {a-3d,a-d,a+d,a+3d}

If all terms of an AP are multiplied with k or divided with k, the resultant series will also be an AP with the common difference dk or d/k respectively.

Offer running on EduRev: __Apply code STAYHOME200__ to get INR 200 off on our premium plan EduRev Infinity!

116 videos|131 docs|131 tests