1/4 of 3/5 of 6/5 of a number is 54 what is the number?

If 3x – 5y = 5 and x/x + y = 5/7, then what is the value of x – y ?

If √18x14xX=84 then x equals:

 (3² * 4² * 5) ÷ 36 = (?)²-80

If a + b + c = 13, a² + b² + c² = 69, then find ab + bc + ca.

If in a code, 52 – 36 = 97 and 46 – 78 = 1510, then how 53 – 62 can be encoded?

The value of 1001 + 11 of 13 is:

415% of 620 =?

(2√27-√75+√12) is equal to:

76% of (?) – (11)² = 525