Asit Das Gupta and Alok Kumar Solutions for Exercise 3: Revision Exercise 1

In $7803*$ replace $*$ by the smallest digit to make it divisible by $11$.

In $27*6854$ replace $*$ by the smallest digit to make it divisible by $11$. 

In $*9076845$ replace by $*$ the smallest digit to make it divisible by $11$.

In $6*259$ replace $*$ by the smallest digit to make it divisible by $9$. 

In $870*3892$ replace $*$ by the smallest digit to make it divisible by $9$.

In $10935*2$ replace $*$ by the smallest digit to make it divisible by $9$.

Four bells toll together at  $8 \mathrm{a}.\mathrm{m}$.They toll after  $7,8,11$ and $12 \mathrm{seconds}$ respectively. After how much time will they toll together?

The $\mathrm{HCF}$ and $\mathrm{LCM}$ of two numbers are $24$ and $5544$ respectively. When the first number is divided by $2$, the quotient is $252$ leaving no remainder. Find the other number.