1 . A pineapple costs Tk 7 and a watermelon costs Tk 5. Rahim spent exactly Tk 38 on these fruits. What was the number of pineapples purchased?

• A. 2
• B. 3
• C. 4
• D. Can not be calculated
• D. None of these

Answer: Option C

Explanation:

"Rahim spent exactly 38 Tk on both type of fruits. If he bought only one watermelon and used the rest (38 - 5)  =  33 on pineapple, it would not be 'exact' as 33 can not be divided by 7 (the price of one pineapple)
2 watermelon, 4 pineapple  =  2  ×  5  +  4  ×  7  =  38 Tk
3 watermelon, 3 pineapple  =  3  ×  5  +  3  ×  7  =  36 Tk
So, only by buying 4 pineapples and 2 watermelon Rahim can spend exactly Tk 38."