If 2 is added to each even digit and 1 is subtracted from each odd digit in the number 621754, then what will be the sum of number/numbers not repeated in the new number?

If the ratio of two numbers is 13 : 15 and their L.C.M. is 39780. So are the numbers?

If the mathematical operator ‘÷ ’ means ‘×’, ‘+’ means ‘–’, ‘×’ means ‘+’ and ‘–’ means ‘÷ ’, then 24+48–12×4÷ 2=?

If ‘×’ denotes ‘ – ‘. ‘+’ denotes ‘×’ . ‘÷’ denotes ‘+’ and ‘ – ‘ denotes ‘÷’. Then Find out the value of the following equations.
175 – 25 ÷ 5 + 20 × 3 + 10=?

If ‘+’ means ‘-‘, ‘-‘ means ‘x’, ‘x’ means ‘÷’ and ‘÷’ means ‘+’, then what will be the value of the  following expression?
27 – 2 + 24 × 8 ÷ 4

If “S” denotes “multiplied by”, “V” denotes "subtracted from", "M" denotes "added to" and "L" denotes "divided by", then
96 L 8 S 4 V 16 M 9 = ?

If in a certain way, 3 + 4 = 25 and 7 + 24 = 625, then Find the value of 9 + 40 =?

Two years ago, Roshni's age was 3 times her son's age, and 2 years later, 2 times her age would be 5 times her son's age. Find the current age of Roshni.