If a number $x$ is $10 \%$ less than another number $y$ and $y$ is $10 \%$ more than $125,$ then $x$ is equal to

Two-fifths of one-third of three-seventh of a number is $15$. What is $40$ per cent of that number?

When the price of a product was decreased by $10 \%$,the number sold increased by $30 \%$. What was the effect on the total revenue (in $\%$)?

$1200$ boys and $650$ girls appeared in an examination. If $70 \%$ of boys and $40 \%$ of girls failed,find the approximate percentage of passed students.

If one number is $80 \%$ of the other and $4$ times the sum of their squares is $656,$ then the numbers are:

$A$ scored $30\%$ marks and failed by $15$ marks. $B$ scored $40\%$ marks and obtained $35$ marks more than that required to pass. The pass percentage is: (in $\%$)