Question

You have to find out what will come in place of the question mark
$\sqrt{486}$++ 21% of 32 =?

• A. 35
• B. 40
• C. 20
• D. 28
• E. 32

Answer 1

Answer: (D)

28

Answer 2

1.Calculate $\sqrt{486}$
$\sqrt{486} = \sqrt{9 \times 54} = 3\sqrt{54} \approx 3\sqrt{49 + 5} \approx 3\sqrt{49} + 3\sqrt{5} \approx 7 + 3\sqrt{5}$
2.Calculate 21% of 32 :
21% of 32 =$\frac{21}{100}$x 32=$\frac{672}{100}$=6.72
Add the results from steps 1 and 2 :
$(7+\sqrt{5}​)+6.72≈13.72+\sqrt5​$
Now, let's determine which of the provided options is closest to this result:
(1) 35 (2) 40 (3) 20 (4) 28 (5) 32
None of the options exactly equals 13.72+$\sqrt{5}$​, but option (4) is the closest. Thus, the best approximation to the result is 28.
The Correct option is(D)