Word Problem 8

Percentage Comparison 0

Problem 8: A reduction of 20% in the price of sugar enables a purchaser to buy 4 kgs more for Rs 80. The original price of 1 kg of sugar was;

a) Rs 4 b) Rs 4.50 c) Rs 8 d) Rs 5.50

(word problems on job exam mathematics.)

Solution:

We suppose;

Original price of sugar per kg $= y Rs$

It means y rupees is equal to 1 kg of sugar i-e

$\Rightarrow yRs = 1 kg$

Now we calculated quantity of sugar in 80 Rs according to original price, so, from above we get;

$1 Rs = \frac{1 kg}{y}$

Multiply both sides by 80

$\Rightarrow80 Rs = \frac{80 kg}{y}$

Now we come to new price per kg, after reduction of 20 % in original price. i-e after reduction of $\frac{20}{100}y$ per kg. But new price per kg is calculated by subtracting reduction from original price i-e;

New Price

$=y - \frac{20}{100}y$

$= \frac{100 y - 20 y }{100}$

$= \frac{80y }{100}$

This simply means now 1 kg of sugar can be bought in Rs $\frac{80y }{100}$ . We can write;

$\frac{80y }{100} = 1 kg$

$\Rightarrow y Rs = \frac{100}{80}$

$\Rightarrow 1 Rs = \frac{100}{80y}$

Now we will calculate quantity of sugar in 80 Rs according to New Price ( After Reduction);, So multiply both sides by 80;

$\Rightarrow 80 Rs = \frac{100}{80y}\times 80$

$\Rightarrow 80 Rs = \frac{100}y}$

But according to condition of question, this quantity of sugar in Rs 80 as per new price should be 4 kg more than quantity of sugar in 80 Rs as per original price ! i-e we will add 4 kg more to $\frac{80 kg}{y}$ , then both quantities of Rs 80 will be equal!