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

D. 420÷60=7

Step-by-step explanation:

Given expression,

Since, 533 to nearest ten = 540,

And, 57 to nearest ten = 60,

Now, nearest fifty of 533 = 550,

And, nearest fifth of 57 = 55,

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,

When we analyse above explanation,

we observed that answer is approximately 9 or 10.

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