If $\frac{144}{0.144} = \frac{14.4}{x}$,then the value of $x$ is

$(1.06+0.04)^{2}-?=4 \times 1.06 \times 0.04$

In a certain college,the number of girls is twice the number of boys. $\frac{1}{5}$ of the girls and $\frac{1}{8}$ of the boys took part in a social camp. What part of the total number of students took part in the camp?

What is the value of $\frac{5.6 \times 0.36 + 0.42 \times 3.2}{0.8 \times 2.1} ?$

What is $x$ if $x^{2} - 1.5^{2} - 0.9^{2} = 2.43$?

What approximate value will come in place of the question mark $(?)$ in the given equation? (You are not expected to calculate the exact value)
$\frac{1810}{24.05} \times 7.95 + 11.02 \times 18.88 = ? - 306$