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If p - q = 3 and
\begin{aligned} p^2 + q^2 = 29 \end{aligned}, find the value of pq.

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  • 10

Answer: Option D

Explanation:

We know
\begin{aligned} 2ab = (a^2 + b^2) - (a - b)^2 \end{aligned}

\begin{aligned} 2pq = 29 - 9 = 20 \end{aligned}

\begin{aligned} =>pq = 10 \end{aligned}

Similar Questions :

1. If a - b = 3 and \begin{aligned} a^2 + b^2 = 29 \end{aligned}, then find the value of ab

  • 7
  • 8.5
  • 10
  • 12

Answer: Option C

Explanation:

Remember the formula, if not then cram it :)
\begin{aligned} 2ab = (a^2 + b^2)- (a-b)^2 \end{aligned}
=> 2ab = 29 - 9 = 20
=> ab = 10

2. (3080 + 6160) / 28

  • 380
  • 350
  • 330
  • 310

Answer: Option C

Explanation:

As per BODMAS rule, first we will solve the equation in bracket then we will go for division
= (9240)/28 = 330

3. Find the value of X
X = (6/119) * (63/8) * (17/9)

  • 1/4
  • 2/4
  • 3/4
  • 4

Answer: Option C

4. \begin{aligned}
(3\frac{1}{4}\div \{1\frac{1}{4} - \frac{1}{2}(2\frac{1}{2} - \overline {\frac{1}{4} - \frac{1}{6}} ) \} )
\end{aligned}

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  • 108

Answer: Option A

Explanation:

Tip:
As you can see, there is bar over
\begin{aligned}
\overline{\frac{1}{4}-\frac{1}{6}}
\end{aligned}
So their sign will be changed from - to + as
\begin{aligned}
\frac{1}{4}+\frac{1}{6}
\end{aligned}

5. 100 + 50 * 2 = ?

  • 200
  • 150
  • 100
  • 300

Answer: Option A

Explanation:

After applying BOMAS rule,
First Multiplication will be done then addition
So it will be 100 + 100 = 200

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