1 The robber had left/had been leaving before the police arrived. 2 He was angry because somebody had been taking/had taken his keys. 3 How long had you been waiting/had you waited before the ambulance arrived? 4 By the time we got there, the firefighters had put out/had been putting out the fire. 5 They were tired because they worked/had been working all night.

Given a bag with 7 blue and 3 red marbles. If sipho draws out 2 marbles withad with replacement 1. determine the probability of selecting bwo green morbles 2. Selecbing a blue marble first and then a green marble 3. Selecting at least one red marble. 4. \( P(B B \) or \( B R \) or \( R B \) )

The summation of probability of an event and its complement is equal to 1.0

8. Considera o conjunto \( C=\{-\sqrt{7}, \pi\} \). Em qual dos seguintes conjuntos está contido \( C \) ? \( \begin{array}{llll}\text { [A] }]-\sqrt{7}, \pi] & \text { [B] }[-\sqrt{7}, \pi[ & [C]]-\infty,-\sqrt{7}] \cup] \pi,+\infty[ & \text { [D] }[-\sqrt{7},+\infty\end{array} \)

समांतर चतुभुज \( x \)-अक्ष और \( (3,-1) \) और \( (4,-2) \) बिंदुओं को मिलाने वाली रेखा के बीच का कोण ज्ञात कींकि, एक रेखा की ढाल दूसरी रेखा की ढाल का दुगुन है। यदि दोनों के बीच के कोण की स्योंग्र

\( \left. \begin{array} { l } { F = \frac { 2 \sqrt { 20 } } { \sqrt { 15 } } \times \frac { \sqrt { 27 } } { 3 \sqrt { 7 } } \times \frac { \sqrt { 84 } } { \sqrt { 48 } } ; G = \sqrt { \sqrt { 13 } - \sqrt { 11 } } \times \sqrt { \sqrt { 13 } + \sqrt { 12 } } \times \sqrt { 2 } } \\ { H = ( \sqrt { 4 - \sqrt { 15 } } + \sqrt { 4 + \sqrt { 15 } } ) ^ { 2 } ; I = ( \sqrt { \sqrt { 3 } + 5 } ) ^ { 4 } ; J = \sqrt { ( 3 \sqrt { 2 } - 2 \sqrt { 5 } ) ^ { 2 } } } \\ { H = \sqrt { 7 + 4 \sqrt { 3 } } ; L = \sqrt { 8 - 2 \sqrt { 12 } } ; M = \sqrt { 29 - 12 \sqrt { 5 } } } \end{array} \right. \)