Question

Ramu marked a dot in the first square, 2 dots in the 2nd square,3 dots in the 3rd square and so on. then find the total number of squares required to mark a total of 55 dots.​

Answer 1

Answer:

10

Step-by-step explanation:

sum of first n numbers=n(n+1)/2

here the sum us 55

we have to find n

n(n+1)/2=55

n²+n-110=0

factorise

you should get n=10 & n=-11

here the number of squares shoud be positive

so choose

n=10