If '$+$' means 'subtraction', '$\div$' means 'addition', '$-$' means 'multiplication' and '$\times$' means 'division', then what is the value of $(8 + 2 - 19) - (4 + 27 \times 3)$?
The problem requires substituting mathematical symbols based on a given code and then evaluating the expression using the standard order of operations (BODMAS/PEMDAS).
First, let's establish the new meaning for each symbol as defined:
The original expression is: $(8 + 2 - 19) - (4 + 27 \times 3)$
Now, apply the symbol substitutions to the entire expression:
The transformed expression is: $(8 - 2 \times 19) \times (4 - 27 \div 3)$
Evaluate the expression using the order of operations (Parentheses/Brackets, Orders/Exponents, Division and Multiplication (left-to-right), Addition and Subtraction (left-to-right)).
The value of the expression after applying the symbol substitutions and evaluating according to the order of operations is 150.
Study the given pattern carefully and select the numbers from among the options that can replace the question marks (?).
Study the given pattern carefully and select the number from among the given option that can replace the question mark (?).

Which two numbers (not digits) should be interchanged to make the given equation correct?
21 × 8 – 18 + (64 ÷ 2) + 32 = 64
The two expressions on either side of the equal sign will have the same value if two numbers on the left-hand side are interchanged and two signs on the right-hand side are interchanged. What are those two numbers (not digits) and the two signs?
9 × 1 ÷ 3 + 8 – 7 = 12 ÷ 3 + 2 × 33 – 13
Select the set, from the given options, in which the numbers are related in the same way as are the numbers of the following sets.
(NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into its constituent digits. E.g. 13 – Operations on 13 such as adding/subtracting/multiplying etc. to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed.)
(6, 13, 78)
(5, 22, 110)
If + means -, - means ×, × means ÷, ÷ means +, then what will come in place of the question mark (?) in the following equation?
28 - 6 ÷ 4 + 14 × 14 = ?
In the following number-pairs, the second number is obtained by applying certain mathematical operations to the first number. Which numbers should replace X and Y so that the pattern followed by the two numbers on the left side of :: is the same as that on the right side of :: ?
(NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into its constituent digits. E.g. 13 Operations on 13 such as adding/subtracting /multiplying etc. to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed.)
X : 649 :: 956 : Y