is the classification for a solid instrument that produces sound when it is hit, scraped, or struck. A. Chordophone B. Idiophone C. Aerophone D. Membranophone

Westside' and 'Westcoast' hand signs [GENERAL / AMERICA].

Which of the following statements islare TRUE of the major schools of economic thought? i. Keynesians believe in the use of macroeconomic tools to stabilise the economy whereas the others do not. ii. Monetarists believe that monetary policy is more effective than fiscal policy in eliminating unemployment, whereas Keynesians believe the opposite. iii. Supply-siders believe that incentives to work, save and invest are more important than macroeconomic demand manipulation in managing the economy. iv. The classical economists believed that the monetary and real sides of the economy wereentirely separate, whereas the other schools believe that the monetary sector can affecthe real economy, at least in the short run. a) i b) i and ii c) i, iii and iv d) ii, iii and iv

3.20. Para \( n \in \mathbb{Z}^{+} \)se define \( f(n) \) como el número de enteros positivos \( <n \) que son primos relativos con \( n \), por ejemplo \[ \begin{aligned} f(1)=1, \\ f(2)=1, \\ f(3)=2, \\ f(4)=2\end{aligned} \] 3.20.1. Calcular \( f(10), f(13), f(18), f(24) \) \( \begin{array}{l}\text { 3.20.2. Para } n=12,18,19,25 \text { calcule } \\ \text { 3.20.3. Infiera una fórmula para } \\ \qquad\end{array} \)

3.20. Para \( n \in \mathbb{Z}^{+} \)se define \( f(n) \) como el número de enteros positivos \( <n \) que sc primos relativos con \( n \), por ejemplo \[ \begin{aligned} f(1)=1, \\ f(2)=1, \\ f(3)=2, \\ f(4)=2 .\end{aligned} \] 3.20.1. Calcular \( f(10), f(13), f(18), f(24) \). 3.20.2. Para \( n=12,18,19,25 \) calcule 3.20.3. Infiera una fórmula para \[ \sum_{d \mid n} f(d) . \] donde \( n \in \mathbb{Z}^{+} \). \( \sum_{d \mid n} f(d) \),

Decide whether the following statement is true or false. The graph of \( y=-f(x) \) is the reflection about the \( x \)-axis of the graph of \( y=f(x) \). Choose the correct answer below. False True