Simplify 78−[5+3(25−2×10)]
A.58
B.12
C.30
D.75

To simplify the given expression step by step:

Expression:
78 − [5 + 3(25 − 2 × 10)]

Step 1: Simplify the innermost parentheses.
In the term (25 − 2 × 10), perform the multiplication first:
2 × 10 = 20.
Now the expression becomes:
78 − [5 + 3(25 − 20)].

Step 2: Simplify the parentheses further.
25 − 20 = 5.
The expression now is:
78 − [5 + 3(5)].

Step 3: Simplify the multiplication inside the brackets.
3 × 5 = 15.
The expression becomes:
78 − [5 + 15].

Step 4: Simplify inside the brackets.
5 + 15 = 20.
The expression now is:
78 − 20.

Step 5: Perform the subtraction.
78 − 20 = 58.

Final answer: 58
Correct option: A