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If the sum of two numbers is 11 and the sum of their squares is 65, then the sum of their cubes will be:
Let the two numbers are $$a$$ and $$b$$
Given, Sum of their squares = 65
$$=$$> $$a^2+b^2=65$$ ...................(1)
Sum of two numbers = 11
$$=$$> $$a+b=11$$
$$=$$> $$\left(a+b\right)^2=11^2$$
$$=$$> $$a^2+b^2+2ab=121$$
$$=$$> $$65+2ab=121$$
$$=$$> $$2ab=56$$
$$=$$> $$ab=28$$ ............................(2)
$$\therefore\ $$Sum of their cubes = $$a^3+b^3$$
$$=\left(a+b\right)\left(a^2+b^2-ab\right)$$
$$=\left(11\right)\left(65-28\right)$$
$$=\left(11\right)\left(37\right)$$
$$=407$$
Hence, the correct answer is Option A
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