12
Q:

# The tax on an article decreases by 10% and its consumption increases by 10%. Find the effect percent on its revenue?

Q:

Lucky started working 2 years ago. Her starting salary was half of Karthik's salary at that time. Each year since then Lucky and Karthik have received a rise of 10% in their respective salary. What percentage (to the nearest percent) of Karthik's current salary is Lucky's current salary ?

 A) 75% B) 22.5% C) 35% D) 50%

Explanation:

Let the salary of Karthik 2 years ago be Rs.100
So, Lucky's salary 2 years ago was Rs.50

Karthik's present salary has seen two 10 percent increases. So as Lucky's salary.

So, Karthik's salary 1 year ago = 100 + 10% of 100 = 100 + 10 = 110.
Karthik's present salary = 110 + 10% of 110 = 110 + 11 = 121.

Lucky's salary 1 year ago = 50 + 10% of 50 = 50 + 5 = 55
Lucky's present salary = 55 + 10% of 55 = 55 + 5.5 = 60.5

Lucky's present salary of 60.5 = 50% of Karthik's present salary of 121.

6 105
Q:

Madhu got 32% of the maximum marks in a Bank examination and failed by 8 marks. However, Kumar who took the same examination got 42% of the total marks and got 16 marks more than the cut-off marks. What was the cut-off marks in the examination ?

 A) 76.8 B) 86.8 C) 78.8 D) 84.8

Explanation:

Let 'M' be the maximum marks in the examination.

Therefore, Madhu got 32% of M = 32M/100 = 0.32M
And Kumar got 42% of M = 42M/100 = 0.42M.
In terms of the maximum marks Kumar got 0.42M - 0.32M = 0.1M more than Madhu. ---- (1)

The problem however, states that Kumar got 16 marks more than the cut-off mark and Madhu got 8 marks less than the cut-off mark. Therefore, Kumar has got 16 + 8 = 24 marks more than Madhu. ---- (2)

Now, Equating (1) and (2), we get
0.1M = 24 => M = 24/0.1 = 240
'M' is the maximum mark and is equal to 240 marks.
We know that Madhu got 32% of the maximum marks.
Therefore, Madhu got 32 x 240/100 = 76.8 marks.
We also know that Madhu got 8 marks less than the cut-off marks.

Therefore, the cut-off marks will be 8 marks more than what Madhu got
= 76.8 + 8 = 84.8.

4 172
Q:

A house owner wants to get his house painted. He is told that this would require 45 kg of paint allowing 6% wasting. And if the paint is available in 4 kg tins only, the number of tins required for painting the house is ?

 A) 12 B) 13 C) 11 D) 10

Explanation:

Given 45 kg for painting

And 6% 0f 45 for wasting => 6x45/100 = 2.7 kg

Now total paint required = 45+2.7 = 47.7 kgs

But tins are available in only 4kgs

Then, no. of tins req = 47.7/4 = 11.4 => 12 tins

4 162
Q:

If the price of diesel increases by 25% and Karthik intends to spend only an additional 15% on diesel, by how much % will he reduce the quantity of diesel purchased ?

 A) 6.67 % B) 8 % C) 7.41 % D) 9 %

Explanation:

Let the price of 1 litre of diesel be Rs.x and let Karthik initially buy 'y' litres of diesel.
Therefore, he would have spent Rs. xy on diesel.

When the price of diesel increases by 25%, the new price per litre of diesel is 1.25x.

Karthik intends to increase the amount he spends on diesel by 15%.
i.e., he is willing to spend xy + 15% of xy = 1.15xy

Let the new quantity of diesel that he can get be 'q'.
Then, 1.25x x q = 1.15xy
Or q = (1.15/1.25)y = 0.92y.

As the new quantity that he can buy is 0.92y, he gets 0.08y lesser than what he used to get earlier.

Or a reduction of 8%.

3 216
Q:

In an election between two candidates K and L, the number of valid votes received by K exceeds those received by L by 15% of the total number of votes polled. If 20% of the votes polled were invalid and a total of 8720 votes were polled, then how many valid votes did L get ?

 A) 3241 B) 2457 C) 2642 D) 2834

Explanation:

Let the total number of votes polled in the election be 100k.
Number of valid votes = 100k - 20% (100k) = 80k
Let the number of votes polled in favour of K and L be a and b respectively.
a - b = 15% (100k) => a = b + 15k
=> a + b = b + 15k + b
Now, 2b + 15k = 80k and hence b = 32.5k
It is given that 100k = 8720
32.5k = 32.5k/100k x 8720 = 2834

The number of valid votes polled in favour of L is 2834.