3
Q:

# The price of commodity X increases by 40 paise every year, while the price of commodity Y increases  by 15 paise every year. If in 2001, the price of commodity X was Rs. 4.20 and that of Y was Rs. 6.30, in which year commodity X will cost 40 paise more than the commodity?

 A) 2010 B) 2011 C) 2012 D) 2013

Explanation:

Suppose commodity X wil cost 40 paise more than Y after Z  years. Then,

(4.20 + 0.40Z) - (6.30 + 0.15Z) = 0.40

$\inline&space;\fn_jvn&space;\Leftrightarrow$  0.25Z = 0.40 + 2.10  $\inline&space;\fn_jvn&space;\Leftrightarrow$  Z= $\inline&space;\fn_jvn&space;\frac{2.50}{0.25}&space;=\frac{250}{25}=10$

$\inline&space;\fn_jvn&space;\therefore$ X will cost 40 paise more than Y 10  years after 2001 . i.e in 2011

Q:

Evaluate : $\inline \fn_jvn \small \frac{3.39^{2}-2.61^{2}}{3.39-2.61}$ ?

 A) 3 B) 4 C) 6 D) 1

Explanation:

Given $\inline \fn_jvn \small \frac{3.39^{2}-2.61^{2}}{3.39-2.61}$ = $\inline \fn_jvn \small \frac{a^{2}-b^{2}}{a-b}$ = $\inline \fn_jvn \small \frac{(a+b)(a-b)}{a-b} = (a+b)$ = 3.39 + 2.61 = 6.

2 36
Q:

Karthik read $\inline \fn_jvn \small \frac{6}{13}$ th of a book in 1st week and $\inline \fn_jvn \small \frac{5}{9}$ th of the remaining book in 2nd week. If there were 100 pages unread after 2nd week, how many pages were there in the book ?

 A) 404 B) 415 C) 418 D) 420

Explanation:

Let the total book be 1
Then, in the 1st week $\inline \fn_jvn \small \frac{6}{13}$th of book is read
i.e remaining pages = $\inline \fn_jvn \small 1-\frac{6}{13} = \frac{7}{13}$
in 2nd week he read $\inline \fn_jvn \small \frac{5}{9}$th of it
i.e $\inline \fn_jvn \small \frac{5}{9}$ $\inline \fn_jvn \small \times \frac{7}{13} = \frac{35}{117}$
remaining pages after 2nd week = $\inline \fn_jvn \small \frac{7}{13}-\frac{35}{117} = \frac{28}{117}$
But given remaining pages after 2nd week = 100
$\fn_jvn&space;\small&space;\Rightarrow$ $\inline \fn_jvn \small \frac{28x}{117} = 100$
$\fn_jvn&space;\small&space;\Rightarrow$   x = 418

$\fn_jvn&space;\small&space;\therefore$ The total pages in the book are 418

6 93
Q:

$(0.2 * 0.2+0.01)(0.1 * 0.1+0.02)^{-1}$ is equal to

 A) 5/3 B) 9/5 C) 41/4 D) 41/12

Explanation:

Given expression = $\inline&space;\fn_jvn&space;\frac{(0.2\times&space;0.2+&space;0.01)}{(0.1\times&space;0.1&space;+0.02&space;)}=\frac{0.04+0.01}{0.01+0.02}=\frac{0.05}{0.03}=\frac{5}{3}$

3 700
Q:

When 52416 is divided by 312, the quotient is 168. what will be the quotient when 52.416 is divided by 0.0168?

 A) 3.12 B) 312 C) 3120 D) None of these

Explanation:

Given , $\inline&space;\fn_jvn&space;\frac{52416}{312}=168&space;\Leftrightarrow&space;\frac{52416}{168}=312$

Now,  $\inline&space;\fn_jvn&space;\frac{52.416}{0.0168}=\frac{52416}{16.8}=\frac{52416}{168}\times&space;\frac{1}{10}=(312\times&space;10)=3120$

6 765
Q:

54.327 x 357.2 x 0.0057 is same as

 A) 5.4327 x 3.572 x5.7 B) 5.4327 x 3.572 x0.57 C) 54327 x 3572 x 0.0000057 D) None of these

Explanation:

Number of decimal places in the given expression = 8

Number of decimal places in (A) = 8

Number of decimal places in (B) = 9

Number of decimal places in (C)= 7

Clearly , the expresssion in (A) is the same as the given Expression.