The Yajurveda, one of the four Vedas, contains references to the decimal system, including the use of the terms "dasha" (ten) and "shatam" (hundred).

Aryabhata, an Indian mathematician and astronomer, is widely recognized for introducing the concept of zero as a mathematical entity in the 5th century CE.

The decimal system was primarily developed in India to facilitate astronomical calculations, particularly for tracking the movement of celestial bodies and predicting eclipses.

Brahmagupta, an Indian mathematician and astronomer, made significant contributions to the development of the decimal system and the concept of zero in the 7th century CE.

The decimal point is used to separate the integer part of a number from the fractional part, allowing for the representation of both whole numbers and fractions in a single system.

Bhaskara II, an Indian mathematician and astronomer, made significant contributions to the decimal system and the concept of zero in the 12th century CE.

The mathematical symbol "0" is used to represent zero in the decimal system.

Srinivasa Ramanujan, an Indian mathematician, made significant contributions to the decimal system and the concept of zero in the 19th century CE.

The base of the decimal system is 10, which means that it uses ten digits (0, 1, 2, 3, 4, 5, 6, 7, 8, 9) to represent numbers.

The decimal system is used in everyday life for various purposes, including currency, measurement, and timekeeping.

Zero plays a crucial role in mathematical operations, allowing for the representation of negative numbers, enabling the concept of place value, and facilitating the operations of addition and subtraction.

None of the listed mathematicians made significant contributions to the decimal system and the concept of zero in the 20th century CE.

To convert the binary number 1011 to decimal, we multiply each digit by its corresponding power of 2 and add the results. 1 * 2^3 + 0 * 2^2 + 1 * 2^1 + 1 * 2^0 = 8 + 0 + 2 + 1 = 11.

To convert the hexadecimal number 1A to decimal, we multiply each digit by its corresponding power of 16 and add the results. 1 * 16^1 + 10 * 16^0 = 16 + 10 = 26.

To convert the octal number 75 to decimal, we multiply each digit by its corresponding power of 8 and add the results. 7 * 8^1 + 5 * 8^0 = 56 + 5 = 61.