In a stack of red and blue T-shirts, blue T-shirts and red T-shirts are in the ratio \( 4: 3 \). If then are 49 T-shirts, find the ratio of blue \( T \)-shirts to the total number of T-shirts-

en \( \sqrt{2+\sqrt{3}}+\sqrt{2-\sqrt{3}} \) is

Nếu \( x = 9 \), tính giá trị của \( \sqrt{x} \) và \( \sqrt[3]{x} \).

Given: \[ \begin{array}{l}f(x)=x-5 \quad g(x)=\left\lceil\frac{x}{6}\right\rceil \\ (f \circ g)(4)=\text { Ex: } 15\end{array} \]

La cantidad de un material radiactivo disminuye a la mitad cada 10 años. Si comenzamos con 80 gramos, ¿cuánto quedará después de 30 años?

1. Choose the correct answer from the given ones : \( \begin{array}{llll}\text { 1 If } X=\{2\}, Y=\{3,4\} \text {, then } n\left(X^{2}\right) \times \mathrm{n}(\mathrm{Y})=\ldots \ldots \ldots \ldots \\ \begin{array}{llll}\text { (a) } 1 & \text { (b) } 2 & \text { (c) } 3 & \text { (d) } 4\end{array}\end{array} \).