A student multiplies a number with 7.2 instead of 0.72. If due to this answer is 2592 more than the right answer, then what was the original number? 

Direction : What should come in place of the question (?) in the following question.

8424÷ 135 ×6=?

Direction : What should come in place of the question (?) in the following question.

8934 – 3257 + 481 = ? + 2578

N is the smallest three digit prime number. When N is divided by 13, then what will be the remainder? 

A six digit number is formed by writing a three digit number two times consecutively. Find the least four digit number which can exactly divide this type of six digit number.

The total cost of 18 pens and 23 pencils is Rs. 231, while the total cost of 7 pens and 13 pencils is Rs. 102. What is the cost of 4 pens and 9 pencils?

0.1 and   $${5\over 8}$$ of a bamboo are in mud and water respectively and the rest of length 2.75 m is above water. What is the length of the bamboo? 

Direction : What should come in place of the question (?) in the following question.

23.56 + 134.44+ 4142.25=?