In the following question, which of the two signs will be interchanged to get the correct equation?
$$119 - 21 \div 7 + 117 \times 3 = 11$$

Option (a) $$\div\ and\ \times$$

$$119 - 21 \times 7 + 117 \div 3 = 11$$

119 - 147 + 39 = 11

11 = 11

The given equation is satisfied. So this is the correct answer.

Option (b) $$-\ and\ \times$$

$$119 \times 21 \div 7 + 117 - 3 = 11$$

$$119 \times 3 + 114 = 11$$

357 + 114 = 11

$$471\ne\ 11$$

The given equation is not satisfied. So this is not the correct answer.

Option (c) $$-\ and\ +$$

$$119 + 21 \div 7 - 117 \times 3 = 11$$

$$119 + 3 - 351 = 11$$

$$-229\ \ne\ 11$$

Option (d) $$\div\ and\ +$$

$$119 - 21 + 7 \div 117 \times 3 = 11$$

The given equation is not satisfied. Becasue it will give the values in fraction. So this is not the correct answer.