Question

A condominium building has 25 condo units. Each unit has 5 windows. Ryder said that there are 125 windows altogether.

Which estimate can be used to see if Ryder’s answer is reasonable? Is Ryder correct?

A.
30 × 5
The answer is not reasonable. Ryder is not correct.

B.
30 × 5
The answer is reasonable. Ryder is correct.

C.
30 ÷ 5.
The answer is not reasonable. Ryder is not correct.

D.
30 + 5.
The answer is reasonable. Ryder is correct.

Answer 1

The answer is B, 30 x 5 The answer is reasonable. Ryder is correct. It is reasonable because if 25 x 5 is 125, then 30 x 5 won't be too much to be unreasonable. 30 x 5 is 150, therefore it is only 25 windows higher, so it is reasonable. Hope this helps! :)