` 2 xx 4 xx 6 xx ---------xx 250 `

2xx4xx6xx---------xx250 .

In each of the following questions, some equations are solved on the basis of certain system. Find out the correct answer for the unsolved equation on that basis. 2 xx 4 xx 6 = 4, 9 xx 3 xx 7 = 13, 4 xx 7 xx 6 = 3, 9 xx 7 xx 8 = ?

In each of the following questions, some equations are solved on the basis of certain system. Find out the correct answer for the unsolved equation on that basis. 3 xx 5 xx 7 xx 2 = 24, 2 xx 4 xx 6 xx 8 = 22, 4 xx 4 xx 8 xx 9 = ?

Find the value of 2 xx { ( 3.6 xx 0.48 xx 2.50)/( 0.12 xx 0.09 xx 0.5) }

Find the unit digit of 3^6 xx 4^7 xx 6^3 xx 7^4 xx 8^2 xx 9^5 .

Is 7 xx 6 xx 5 xx 4 xx 3 xx 2 xx 1 +5 a composite number? Justify your answer.

The unit digit of expression (1 xx 2 xx 3 xx 4 xx 5 xx 6 xx 7 xx 8 xx 9 xx 10)/(100) .

Explain why 7 xx 11 xx 13 + 13and 7 xx 6 xx 5 xx 4 xx 3 xx 2 xx 1 + 5 are composite numbers