EASY
AS and A Level
IMPORTANT
Earn 100

In a game, a player attempts to hit a target by throwing three darts. With each throw, a player has a 30% chance of hitting the target.

Draw up the probability distribution table for H, the number of times the target is hit in a game.

Important Questions on Probability Distributions

EASY
AS and A Level
IMPORTANT

In a game, a player attempts to hit a target by throwing three darts. With each throw, a player has a 30% chance of hitting the target.

How many times is the target expected to be hit in 1000 games?

EASY
AS and A Level
IMPORTANT

Two students are randomly selected from a class of 12 girls and 18 boys.

Find the expected number of girls and the expected number of boys.

EASY
AS and A Level
IMPORTANT

Two students are randomly selected from a class of 12 girls and 18 boys.

Write the ratio of the expected number of girls to the expected number of boys in simplified form. What do you notice about this ratio?

EASY
AS and A Level
IMPORTANT

Two students are randomly selected from a class of 12 girls and 18 boys.

Calculate the variance of the number of girls selected.

EASY
AS and A Level
IMPORTANT

A sewing basket contains eight reels of cotton: four are green, three are red and one is yellow. Three reels of cotton are randomly selected from the basket.

Show that the expected number of yellow cotton reels is 0.375.

EASY
AS and A Level
IMPORTANT

A sewing basket contains eight reels of cotton: four are green, three are red and one is yellow. Three reels of cotton are randomly selected from the basket.
Find the expected number of red cotton reels.

EASY
AS and A Level
IMPORTANT

A sewing basket contains eight reels of cotton: four are green, three are red and one is yellow. Three reels of cotton are randomly selected from the basket.
Hence, state the expected number of green cotton reels.

EASY
AS and A Level
IMPORTANT

A company offers a $1000 cash loan to anyone earning a monthly salary of at least $2000. To secure the loan, the borrower signs a contract with a promise to repay the $1000 plus a fixed fee before 3 months have elapsed. Failure to do this gives the company a legal right to take $1540 from the borrower's next salary before returning any amount that has been repaid.

From past experience, the company predicts that 70% of borrowers succeed in repaying the loan plus the fixed fee before 3 months have elapsed.

Calculate the fixed fee that ensures the company an expected 40% profit from each $1000 loan.