Вопрос школьника по предмету Математика
Из 450 луковиц гладиолусов в среднем 90 не прорастают. Какова вероятность того, что случайно выбранная и посаженная луковица прорастёт?
Ответ учителя по предмету Математика
Ответ:
Теория вероятности: P=N/M. N — благоприятные исходы, M — все исходы. N=450-90=360, M=450. P=360/450=0,8
Пошаговое объяснение:
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Умоляю пожалуйста
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One day when she (leave)2 the school the chairman of the school board (come)3 up to her, «Mrs Martin, we (like)4 you (have)5 an assistant as the school (get)6 too large for one little woman. I (go)7 (meet)8 him now.» At that moment a coach (stop)9 at the gate and they (see)10 a young man (jump)11 out of it. He (look)12 strong and active. His eyes (be)13 blue, his hair (be)14 short; but his face (have)15 no expression, it was like a mask. He (introduce)16 to everybody as Charles Twing, the new assistant. The Chairman (think)17 that he never (see)18 such an expressionless face before; he was sure that as soon as Mrs Martin (look)19 at him she (send)20 him away. Mrs Martin asked Mr Twing if he (be)21 at college, and if he ever (teach)22 at a school. It turned out that he never (do)23 such things. The schoolmistress (not say)24 anything to this. She said she (expect)25 him (come)26 to the school early the next day.
The next morning when Mrs Martin came to the school the new assistant (not come)27 yet. But soon he appeared with a crowd of children. They (laugh)28 and (look)29 very happy. Mrs Martin (get)30 angry, but Mr Twing promised that he (listen)31 and (learn)32 very quickly.
A month passed. All (go)33 well in the school. Mrs Martin (begin)34 (like)35 her new assistant and they (become)36 good friends. She never (ask)37 him what he (do)38 before he (become)39 a teacher.
One day a piano (bring)40 to the school as the children (be going)41 (give)42 a concert. Mrs Martin wanted Mr Twing (do)43 something too and he (decide)44 (recite)45 a poem. While he (do)46 it at the concert a voice from the audience shouted, «Bravo, Johnny Walker!» Mr Twing’s face (become)47 white and he (go)48 «away quickly. After the concert Mrs Martin (find)49 Mr Twing in a little room. He (tell)50 her that he (be)51 a clown before he (come)52 to the school.