Question

5. Which is closest in value to √42?

A 5.5
(B) 6
C) 6.5
D 7
How do I solve this

Answer 1

Explanation:

first of all, you could use a calculator and see and compare.

but let's look at this logically :

what fully squared numbers are closest to 42 ?

there is 36 (6²) below, and 49 (7²) above.

so, the solution must be between 6 and 7.

now is 6, 6.5 or 7 closest to the real solution ?

the difference of 6² or 36 to 42 is 6, and the difference of 7² or 49 to 42 is 7.

42 is more or less in the middle.

that means that also the square root will be relatively close to the middle between 6 and 7.

so, 6.5 is the answer.

Answer 2

The closest number to √42 is the option C, 6.5