$\frac{y\ -4}{3}$  + 3y = 4 , find y

 $\frac{b\ +\ \left(b+1\right)+\left(b+2\right)}{4}=\ 21,\ find\ b\$  

 $\frac{y}{7}+\frac{y-4}{3}=\ 2,\ then\ find\ y$  

Mother is 25 years older than her son. Find son’s age if after years ratio of son’s age and mother’s age will be  $\frac{4}{9}$  

Of the three consecutive natural numbers, five times the smallest number is 9 more than four times the greatest number, find the numbers.

Some tickets of Rs 200 and some of Rs 100, of a drama in a theatre were sold. The number of tickets of Rs 200 sold was 20 more than the number of tickets of Rs 100. The total amount received by the theatre by sale of tickets was Rs 37000. Find the number of Rs 100 tickets sold.