Question

The ratio of the prices of a sunglass and a watch is

12:25. Three years later, when the price of the sunglass

rises by 20% and that of watch by Rs. 458.80, the ratio of

their prices becomes 4:9. Find the original price of the sunglass?

A. Rs 520
B.Rs 744
C.Rs 1550
D.Rs 296

Answer 1

The final answer is Rs 1550. I hope the answer is fine !!!

Answer 2

Given :

Ratio of the prices of sunglass and watch = 12 : 25

Rate of growth in price of sunglass = 20%

Amount increased in price of watch = Rs. 458.80

New ratio = 4 : 9

To find : The original price of the sunglass = ?

Solution :

Let the price of sunglass be 12x

Let the price of watch be 25x

After growth,

the price of sunglass would be $12x\times \dfrac{100+12}{100}=12\times \dfrac{120}{100}=12\times 1.2=14.4$

the price of watch would be $25x+458.80$

According to question, we get that

$\dfrac{14.4x}{25x+458.80}=\dfrac{4}{9}\\\\9\times 14.4x=4(25x+458.80)\\\\129.6x=100x+1835.2\\\\129.6x-100x=1835.2\\\\29.6x=1835.2\\\\x=\dfrac{1835.2}{29.6}\\\\x=62$

So, the original price of sunglass would be $12x=12\times 62=744$

Hence, Option 'B' is correct.