Question

Find the total area of 14 squares whose sides are 11 cm, 12 cm,...24 cm

Answer 1

to find the total area of 14 squares we apply the formula for the sum of n natural  nos. which{n(n+1)(2n+1)/6} which gives the sum of squares.

now to find the area we find the squares of nos from 1 to 24 and the subtract the sum of squares of nos from 1 to 10

so the total area= (24 x 25 x 49)/6 - (10 x 11 x 21)/6

                          =4900-385 = 4515 cm²

hope it helps