Question

which equation is not a reasonable estimate for 533÷57. how can you know when an estimate is not reasonable? A. 540÷60=9. B.500÷50=10. C.550÷55=10. D.420÷60=7​

Answer 1

D. 420÷60=7​

Explanation:

Given expression,

`533/ 57`

Since, 533 to nearest ten = 540,

And, 57 to nearest ten = 60,

`\implies 533/ 57\approx 540/ 60 = 9`

Now, nearest fifty of 533 = 550,

And, nearest fifth of 57 = 55,

`\implies 533/ 57\approx 550/ 55 = 10`

Now, nearest hundred of 533 = 500,

Also, 57 is near to 50,

That is, answer will not much affected by taking 50 in the place of 57,

Again nearest hundred of 533 = 500,

`\implies 533/ 57\approx 500/ 50 = 10`

When we analyse above explanation,

we observed that answer is approximately 9 or 10.

Hence, 420÷60=7​ can not be the reasonable estimation.