Question

Which calculation will ALWAYS give a result greater than 1? A.5 × a number less than 1 B.4/9+ a fraction less than 12 C. 1 3/4 - a fraction less than 3/4 D.7/8 × a number less than 1

Answer 1

Answer:

  C.  1 3/4 - (a fraction less than 3/4)

Step-by-step explanation:

Your number sense should be able to help you with this one.

A. 5 × 1/10 = 1/2, not a number greater than 1

B. 4/9 + 1/3 = 7/9, not a number greater than 1

C. 1 3/4 -1/2 = 1 1/4, a number greater than 1 (see below for more explanation)

D. 7/8 × 1/2 = 7/16, not a number greater than 1.

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More explanation

Let x represent a number less than 3/4. Then we want to make sure that ...

  y = 1 3/4 - x

will be greater than 1.

Solving for x, we get ...

  x = 1 3/4 - y

Applying the requirement that x < 3/4, we have ...

  x < 3/4

  (1 3/4 -y) < 3/4

  1 3/4 < y + 3/4 . . . . . . add y

  1 < y . . . . . . . . . . . . . . .subtract 3/4

We see that the condition on x makes sure that y is always greater than 1.