If |p-5| =3 and |q-3| = 5, which of the following statements must be t...
Given
To Find: The options that must be true(for all values of p and q)
Approach
- Since we are given expressions in p and q, we will find the possible values of p and q and then evaluate each of the expression in the options given for their trueness.
- Since, we need to look for must be true statements, any case that makes the expression in the option false will rule out the option.
Working Out
1. As | p – 5| = 3, value of p will be 3 units from away from 5 on the number line. So, following can be values of p:
- p = 5 + 3 = 8 or
- p = 5 – 3 = 2
- So, p = { 2, 8}……….(1)
2. As | q – 3| = 5, value of q will be 5 units away from 3 on the number line. So, following can be values of q:
- q = 3 + 5 = 8 or
- q = 3 – 5 = -2
- So, q = {-2, 8}………(2)
3. Evaluating Options
- p + q > 0 → As p + q = 0, when p = 2 and q = -2, this statement is not always true.
- pq ≥ 0→ Both the possible values of p are positive. For value of q = -2, the value of pq < 0. Hence this statement is not always true
- |p| = |q|→ This statement is not always true, as |p| can be 2 when |q| = 8 or vice versa.
- |p| ≥ |q|→ This statement is not always true, as |p| can be 2 when |q| = 8, in which case we will have |p| < |q|
- -6 ≤ p-q ≤ 10→ We need to find the minimum and maximum value of p – q
- Minimum( p –q) = Minimum p – Maximum q = 2 – 8 = -6
- Maximum(p – q) = Maximum p – Minimum q = 8 – (-2) = 10
- So, value of p –q would always lie between -6 and 10, inclusive. Hence, this statement is always true.
Answer: E
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If |p-5| =3 and |q-3| = 5, which of the following statements must be t...
Understanding the Absolute Value Equations
To solve the equations |p-5| = 3 and |q-3| = 5, we need to determine the possible values for p and q.
Finding p
- The equation |p-5| = 3 implies two scenarios:
- p - 5 = 3 → p = 8
- p - 5 = -3 → p = 2
Thus, p can be 8 or 2.
Finding q
- The equation |q-3| = 5 also implies two scenarios:
- q - 3 = 5 → q = 8
- q - 3 = -5 → q = -2
Thus, q can be 8 or -2.
Analyzing the Statements
Now we evaluate the given options:
- a) p + q 0: Not necessarily true, since p can be 2 or 8 and q can be -2 or 8.
- b) pq 0: Not necessarily true. For example, if p = 2 and q = -2, pq = -4 which is less than 0.
- c) |p| = |q|: Not true in all cases. For example, if p = 8 and q = -2, |p| does not equal |q|.
- d) |p| |q|: Not necessarily true. For example, |p| could be greater or lesser than |q| depending on the combination of their values.
- e) -6 < p="" -="" q="" />< 10:="" let's="" evaluate="" this:="" -="" if="" p="8" and="" q="8," then="" p="" -="" q="0," which="" satisfies="" the="" inequality.="" -="" if="" p="2" and="" q="-2," then="" p="" -="" q="4," which="" also="" satisfies="" the="" inequality.="" -="" if="" p="8" and="" q="-2," then="" p="" -="" q="10," which="" is="" at="" the="" upper="" limit="" but="" still="" satisfies="" the="" condition.="" thus,="" -6="" />< p="" -="" q="" />< 10="" holds="" true="" for="" all="" possible="" values="" of="" p="" and="" q.="" />Conclusion
The correct answer is option 'E': -6 < p="" -="" q="" />< 10.="" />