Question

Question 70 (iii)

Work out the following multiplication.

$12345679\ast 9\_\_\_\_\_\_\_\_\_\_\_\_\_\_$

Use the result to answer the following questions.

By what number should 12345679 be multiplied to get 888888888?

Answer 1

We have, $12345679\ast 9\_\_\_\_\_\_\_111111111$
Here, we observe that in the product all the digits are same i.e. 1, which is actually the unit digit of the product $9\times 9$, Also, the total of digits in the multiplier is 9.
We have to obtain the number 8 in the product, we should multiply the given number 12345679 by 72 as the sum of its digits is 9 and $2\times 9$ has only digit as 8.