Question

Which of the following statements is not true? (r is a positive integer)

विकल्प

• If p < q, then p – r < q – r

• If p ≥ q, then – pr ≥ – qr

• If p > q, then `p/r > q/r`

• If p ≤ q, then p + r ≤ q + r

Answer 1

If p ≥ q, then – pr ≥ – qr

Explanation:

⇒ p ≥ q

Since, r is positive so – r will be negative.

Multiplying by – r on both sides we get,

⇒ – pr ≤ – qr   ...(As on multiplying by negative number the sign reverses)

∴ – pr ≥ – qr is not true.