# Math Puzzle 4

This math puzzle 4 is on speed,distance,square-root,factors etc.**1)By how much per cent must a motorist increase his speed in order to reduce by 20%, the time taken to cover a certain distance?**

(1) 20 (2) 30 (3) 25 (4) 35

**2) The square root of 0.0081 is:**

(1) 0.09 (2) 0.9 (3) 0.91 (4) 0.009

**3) Choose correct option in the place of question mark:**

2 | 4 | 6 |

18 | ? | 30 |

162 | 196 | 150 |

1458 | 1372 | 750 |

(1) 16 (2) 28 (3) 49 (4) 54

**4) 10 years ago father was seven times as old as his son. 2 years hence twice his age will be equal to five times his son. What is the present age of son?**

(1) 15 years (2) 14 years (3) 13 years (4) 12 years

**5) The factors of x**

^{2}+ xy − 2xyz − 2z are:(1) (x − y)( x + 2z) (2) (x + y)( x − 2z) (3) (x − y)( x − 2z)

(4) (x + y)( x + 2z)

**6) Evaluation of 8**

^{3}× 8^{3}× 8^{-5}is(1) 1 (2) 0 (3) 8 (4) None of these

**7) The simplest form of 1.5 : 2.5 is**

(1) 6 : 10 (2) 15 : 25 (3) 0.75 : 1.25 (4) 3 : 5

**8) Under a scheme of investment, the rate of interest is 4% and the interest is compounded three monthly. What will be the amount if a man invests $ 2000 for 1 year under this scheme?**

(1)$ 2125.54 (2) $ 2081.21 (3) $ 2100.25 (4) $ 2060

**9)10**

^{-2}means:(1) Milli (2) Centi (3) Micro (4) Deci

**10) The simplest form of 12 : 18 is**

(1) 6 : 9 (2) 12 : 9 (3) 9 : 6 (4) 2 : 3

From Math puzzle- 4 to Math Teasers

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