Probability Stations

(b) Donald chooses two of the five cards at random, without replacement. He works out the total number of dots on these two cards. (ii) Find the probability that the total number of dots is an odd number.

The diagram shows five cards.

Two of the cards are taken at random, without replacement.

Find the probability that both cards show an even number.

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Another bag contains 2 green counters and 3 pink counters.

Teresa chooses three counters at random without replacement.

Find the probability that she chooses more pink counters than green counters.

A different bag contains 2 blue marbles, 3 yellow marbles and 4 white marbles.

Huma chooses a marble at random, notes the colour, then replaces it in the bag.

She does this three times.

Find the probability that

all three marbles are yellow,

A different bag contains 2 blue marbles, 3 yellow marbles and 4 white marbles. Huma chooses a marble at random, notes the colour, then replaces it in the bag. She does this three times. Find the probability that all three marbles are different colours.

A bag contains red beads and green beads.

There are 80 beads altogether.

The probability that a bead chosen at random is green is 0.35 .

Find the number of red beads in the bag.

• 52

• 0.65

• 25

A bag contains red beads and green beads.

There are 80 beads altogether.

The probability that a bead chosen at random is green is 0.35 .

Marcos chooses a bead at random and replaces it in the bag.

He does this 240 times.

Find the number of times he would expect to choose a green bead.

• 48

• 84

• 0.65

The table shows information about the time, t minutes, taken for each of 150 girls to complete an essay. A girl is chosen at random. Work out the probability that she took more than 100 minutes to complete the essay.

The table shows information about the time, t minutes, taken for each of 150 girls to complete an essay.Two girls are chosen at random.

Work out the probability that, to complete the essay,

they both took 65 minutes or less,