Question 59

The sum of digits of the number $$N = \sqrt{25^{64} \times 64^{25}}$$ is

Solution

Expression : $$N = \sqrt{25^{64} \times 64^{25}}$$

= $$\sqrt{(5)^{128}\times(2)^{150}}$$

= $$(5)^{64}\times(2)^{75}$$

= $$(2)^{11}\times(10)^{64}$$

= $$2048\times(10)^{64}$$

Thus, there are 68 digits in the numbers and sum of digits = $$2+0+4+8=14$$

=> Ans - (C)


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