Approximation Test 1-Solved questions with detailed explanations for SSC, IBPS, SBI PO, RRB, RBI, CSE, CGL, CHSL, CDA, CSE, UPSC

6)

What approximate value should come in place of the question mark (?) in the given questions?

$8787 \div 343 \times \sqrt{50} = ?$

[IBPS (PO), 2013]

A)
250
B)
140
C)
180
D)
100
E)
280

Answer: Option C

Explanation

Given,

$\begin{array}{l} 8787 \div 343 \times \sqrt{50} = \end{array} ?$

It can be approximated as

= $\begin{array}{l} 8800 \div 350 \times \sqrt{49} =? \end{array}$

Now, follow the order of BODMAS,

We get

= 8800÷350×7=?

= 25×7

= 175 ≈ 180

Hence, Option C is correct.

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Discussion

7)

$\frac{601}{49} \times \frac{399}{81} \div \frac{29}{201} = ?$

[Corporation Bank (PO), 2014]

A)
520
B)
360
C)
460
D)
500
E)
420

Answer: Option E

Explanation

Given,

$\frac{601}{49} \times \frac{399}{81} \div \frac{29}{201} = ?$

It can be approximated as

$\begin{array}{l} \Rightarrow \frac{600}{50} \times \frac{400}{80} \div \frac{30}{200} = ? \\ \Rightarrow \frac{600}{50} \times \frac{400}{80} \div \frac{200}{30} = ? \end{array}$

Now, follow the order of BODMAS,

We get

$\Rightarrow 12 \times 5 \div \frac{20}{3} = ?$

⇒ 4×5×20=?

⇒ 20×20

⇒ 400 ≈ 420

Hence, Option E is correct.

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Discussion

8)

${(\frac{24}{9})}^{2} \times \frac{399}{39} \div \frac{41}{899} = ?$

[BOB (PO), 2011]

A)
1600
B)
1650
C)
1700
D)
1550
E)
1750

Answer: Option E

Explanation

Given,

$\begin{array}{l} {(\frac{24}{9})}^{2} \times \frac{399}{39} \div \frac{41}{899} = ? \end{array}$

It can be approximated as

$\begin{array}{l} {(\frac{24}{8})}^{2} \times \frac{400}{40} \div \frac{41}{899} = ? \end{array} \begin{array}{l} {? = (3)}^{2} \times \frac{400}{40} \times \frac{900}{40} \end{array}$

= 9×10×22.5

= 9×225

= 2025 ≈1750

Hence, Option E is correct.

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Discussion

9)

$7 \frac{7}{12} \times 6 \frac{7}{19} \div 19 \frac{1}{3} = ?$

[BOB (PO), 2011]

A)
9
B)
11
C)
2
D)
5
E)
13

Answer: Option D

Explanation

Given,

$7 \frac{7}{12} \times 6 \frac{7}{19} \div 19 \frac{1}{3} = ?$

It can be approximated as

$= \frac{91}{12} \times \frac{121}{19} \div \frac{28}{3} = ? = \frac{90}{12} \times \frac{120}{20} \times \frac{3}{30} = ? = \frac{45}{10} = ?$

= 4.5 = 5

Hence, Option D is correct.

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10)

1599×199÷49-1398+3877=?

[Syndicate Bank (PO), 2011]

A)
9400
B)
9000
C)
8700
D)
8400
E)
9200

Discussion

Approximation Test-1 (Rounding off to Integers)

Answer: Option C

Answer: Option E

Answer: Option E

Answer: Option D

Answer: Option B