Question

On day 1, Erica puts £1 in her bank. On day 2, she puts in £2, on day 3 she puts in £3 etc. How much money will she have after 100 days

Answer 1

5050

Explanation:

There is a simple formula for this kind of problem where you have to find the sum of consecutive numbers 1 to n:

[n(n+1)] / 2

In this case n is 100 so,

[100(100+1)]/2

[100(101)]/2

10100/2

5050

You can also do this by brute force and just add all consecutive numbers to 100