# Aptitude - Square Root and Cube Root - Discussion

Discussion Forum : Square Root and Cube Root - General Questions (Q.No. 10)

10.

If 5 = 2.236, then the value of | 5 | - | 10 | + 125 is equal to: |

2 | 5 |

Answer: Option

Explanation:

5 | - | 10 | + 125 | = | (5)^{2} - 20 + 25 x 55 |

2 | 5 | 25 |

= | 5 - 20 + 50 |

25 |

= | 35 | x | 5 |

25 | 5 |

= | 355 |

10 |

= | 7 x 2.236 |

2 |

= 7 x 1.118 |

= 7.826 |

Discussion:

11 comments Page 1 of 2.
Sri Satya Kanamarlapudi said:
5 years ago

It can be also rewritten as (√(5) √(5)/2) - (2*√(5)√(5)/√(5))+(5*√(5)).

√(5)/2 - 2√(5) +5√(5).

7√(5)/2 = 7.826.

√(5)/2 - 2√(5) +5√(5).

7√(5)/2 = 7.826.

Kongkon said:
6 years ago

I don't understand. Can anyone explain me please?

Vipinkumar said:
7 years ago

You are right @Mannoj Kumar.

@Anuj.

If we take common term sqrt(5) from each term so that we get;

In first term: sqrt 5[ 1/2 ].

In second term: sqrt5 [10/((sqrt5)/sqrt5)] = sqrt5[10/(sqrt5 * sqrt5)]

= sqrt5[10/5].

In third term: sqrt5[(5 * sqrt5)/sqrt5] = sqrt5[5].

In these three terms, sqrt5 is common and take it outside the bracket and apply it in the expression(question)so we get.

= sq5[ 1/2 - 10/5 + 5].

= 2.236[ 0.5 -2 + 5].

= 2.236 * 3.5.

= 7.82600.

@Anuj.

If we take common term sqrt(5) from each term so that we get;

In first term: sqrt 5[ 1/2 ].

In second term: sqrt5 [10/((sqrt5)/sqrt5)] = sqrt5[10/(sqrt5 * sqrt5)]

= sqrt5[10/5].

In third term: sqrt5[(5 * sqrt5)/sqrt5] = sqrt5[5].

In these three terms, sqrt5 is common and take it outside the bracket and apply it in the expression(question)so we get.

= sq5[ 1/2 - 10/5 + 5].

= 2.236[ 0.5 -2 + 5].

= 2.236 * 3.5.

= 7.82600.

Kanchan said:
7 years ago

How to solve root?

Shradha said:
8 years ago

No need to multiply root five to both side.

Tejas said:
8 years ago

How it come 2 root 5?

Avinash said:
9 years ago

rt5/2 - 10/rt5 + rt125.

Just put value of rt5 and calculate.

2.236/2 - 10/2.236 + 5*2.236 = 7.826.

It's simple.

Just put value of rt5 and calculate.

2.236/2 - 10/2.236 + 5*2.236 = 7.826.

It's simple.

Radhika said:
1 decade ago

Why we multiply with squreroot 5 on both sides.

M.V.KRISHNA/PALVONCHA said:
1 decade ago

Hello Anuj.

root=r.

Given (r5/2)-(10/r5)+r125.

10/r5 = 2*5/r5 = 2r5.

r125 = 5r5

(r5/2)-2r5+5r5

(r5/2)+3r5

(r5+6r5)/2

7r5/2

Subst. given r5 value we get 7.826.

Hope you understood.

root=r.

Given (r5/2)-(10/r5)+r125.

10/r5 = 2*5/r5 = 2r5.

r125 = 5r5

(r5/2)-2r5+5r5

(r5/2)+3r5

(r5+6r5)/2

7r5/2

Subst. given r5 value we get 7.826.

Hope you understood.

Anuj said:
1 decade ago

How you calculate 10/5 ?

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