Kalyani went to a market and purchased some apples,each costing Rs 20 and some watermelones, each coasting Rs.105 How many apples did she purchases
I. The total number of apples and watermelons that she purchased is a prime number.
II The total amount on purchasing apples and watermelons is Rs 850.

Options

A. If the question can be answered using one of the statements alone, but cannot be answered using the other statement alone.
B. If the question can be answered using either statement alone.
C. If the questions can be answered using I and II together but not using I or II alone
D. If the question cannot be answered even using I and II together.

Answer

C

Explanation

Let the purchased number of apples and watermalons each be x and y respectively.
From statement l, x+ y in a prime number, so we can.t find the unique value of x.
From statement II, 20x+105 y=850
`rArr 4x+21y=170`
The pairs of (x,y) satisfying the above equation are (32,2) and (11,6). So unlques value of x is not possible.
Using both the statements, if x=11 and y=6 then only x+y is a prime number and fx+21y =170
So the number of apples Kalyanl purcased is 11