Daily Practice - Higher Plus

A bag holds 10 counters, r of them red. Two are taken without replacement and P(both red) = 2/9. Work out r.

On a histogram the bar for 40 < x ≤ 45 has a frequency density of 1.2. How many values are in that class?On a histogram the bar for 40 < x <= 45 has a frequency density of 1.2. How many values are in that class?

Simplify √80 + √45, giving your answer in the form a √b.Simplify sqrt(80) + sqrt(45), giving your answer in the form a sqrt(b).

f(x) = 4x - 12. Work out the inverse function f^-1(x).f(x) = 4x - 12. Work out the inverse function f^-1(x).

y is directly proportional to x³. When x = 4, y = 128. Work out y when x = 3.y is directly proportional to x^3. When x = 4, y = 128. Work out y when x = 3.