Question

7. (i) Express 64 as the sum of 8 odd numbers.
(ii) 121 as the sum of 11 odd numbers.​

Answer 1

Answer:

i) Suppose x is a odd no.

So sum of 8 odd no.  = 643;

x + x+2+x+4+x+6+x+8+x+10+x+12+x+14 = 64;

8x +56 = 64;

8x = 64-56;

8x = 8;

x = 1;

So odd numbers are = 1,3,5,7,9,11,13,15 and their sum is 64

ii) 121 = (11)2

Therefore, 121 is the sum of first 11 odd natural numbers.

121 = 1 + 3 + 5 + 7 + 9 + 11 + 13 + 15 + 17 + 19 + 21