Monicaa Abhijit Solutions for Chapter: Playing with Numbers, Exercise 3: EXERCISE 19.3

Solve the following:

$1B\times B9B$

Think of a number. Double it. Add $18$. Take away $10$. Halve it. Take away $4$. Now what do you get and why?

SUDOKU $(3\times 3)$
Fill the grid so that every horizontal row, every vertical column and every $3\times 3$ box contains the digits $1$ to $9$, without repeating the numbers in the same row, column or box. (You cannot change the numbers already written in the grid).

Place the digits $1$ to $9$ in the circles so that the sum of three numbers on each diameter equals $15$.

Find the value of $\mathrm{A}, \mathrm{B}, \mathrm{C}, \mathrm{D}$ and $\mathrm{E}$ to complete the number triangle given below:

Fill in the circles with the correct digits.

Fill in the blank squares with $2$-digit prime numbers so that the sum of the numbers in both the horizontal and vertical squares is $161$.

The numbers $1$ to $9$ have been arranged in a pattern of triangles so that the sum along each side of the triangle is $22$. Find another such arrangement of the numbers to make the totals equal.