Verbal Reasoning - Arithmetic Reasoning - Discussion

Thanks for giving the detailed solution.

7 + 7 + 7 + 7 = 28.
5 + 5 = 10.
28 + 10 = 38.

@Bob.

Rs - Rupees.

What does Rs stand for?

I can do this by the method of linear equations in two variable.

"x" spent for pineapple and watermelon = Rs.38.

Cost of pineapple = Rs.7.
Cost of watermelon = Rs.5.

The question is how many pineapples you can purchase ?

Firstly multiply 38 by 7. The remainder will be 10.

According to the question we can purchase 4 pineapples and the balance amount rs 10. We will purchase 02 no of watermelon clearly. This is by with out handling the pen only by mind and quickly answer.

If x is for pineapple, and y is for watermelon.

Then, 7x+5y = 38.

we are asked to get number of pineapples, which is x and not y.

Hence, x = (38-5y)/7.

To achieve a whole number value for pineapple, 38-5y must be divisible by 7.

i.e If 38-5y = 28;
y = 2; and x = ?

No of pineapples = 4

We know the pineapples cost 7 rs each and watermelon 5 rs.

Now the normal approach would be to form a quadratic equation.

7x + 5y = 38.

Since we have two unknowns and one equation, we need to solve this by TRIAL AND ERROR.

Substitute the value of x with every option.

For example when x = 2.

14 + 5y = 38.

5y = 24.

y = 24/5 which is a decimal number and hence x = 2 can't be a solution.

Same case for x = 3.

The only option that satisfies the equation x = 4 which gives why = 2.

Hence C is the correct answer.

If you think logically.

Watermelon each one price is Rs == 5 (always round figure like 5*2 = 10, 5*3 = 15).

Total spent amount = 38 Rs.

Last digit of the total amount is 8 (above 5 table is not matching).

By observation like (7*2 = 14, 7*3 = 21, 7*4 = 28).

That means 7*4+5*2 = 38

In this manner explanation is length.

Just thinking is short.

I can explain it properly.

The total spend amount is 38.
So clearly shows here when purchase 4 pineapples at the rate.
Rs 7 we get total amount 28.
Purchase 2 watermelons at the rate rs 5 we get total amount rs 10.

So 28+10=38.
You cannot purchase 3 pineapples. So 3*7=21/ 38-21=17.
Rs17 it is not sufficient amount for purchase of watermelons.