Question

Doraemon went shopping to buy some toys. He had approximately Rs. 15 in the form of one rupee note and 20 paisa coins. After buying the toys, the number of one rupee notes he has now is equal to the number of 20 paisa coins he had originally and the number of 20 paisa coins he has now is equal to the number of one rupee note had originally. And like many 20 paise coins as he originally had one rupee notes. He actually came back with exactly one-third of what he had started out with. If he originally had x rupees then what is the sum of digits in x*10​

Answer 1

Answer:

9

Step-by-step explanation:

Let us assume that Dorameon had X 1 rupees and Y 20 paise coins. before shopping he had (100 X + 20 Y) paise

after shopping he was left with (100 Y +20 X) paise.

and according to question it was mentioned that he was left with one third of intial amount. So,

3(100 Y +20 X) = 100X + 20 Y

On simplification we get X= 7 Y

Now let us go with hit and trail method

Let Y is 1 then X is 7. Assuming this he had 7.20 rupees initially.

Let Y= 2. Then X= 14. Then, initial sum would be 14.40 rupees

If Y= 3 then the sum will be 21.6 rupees.

if Y > 3 it would be more than 21.6 Rs and better to stop here.

So among these when Y = 2 the initial amount (14.4) is closer to 15 than when Y = 1 or Y = 3.

Therefore the only suitable answer is 14.40 rupees.

So now 14.4*10 = 144

As they asked sum of digits answer would be 1+4+4 = 9