Total no. of buttons = 300 + 700 + 1000
+ 500 = 2500
Possibility for a person to pick a pink button = 300/2500 = (3/25)%
Amount of pink buttons she can expect her friends to pick = 50(3/25) = 6
She can expect to make 6 pink barrettes.
Answer:
distance covered in 2 hours = 80 km
distance covered in 1 hour = 80÷2 = 40 km
distance covered in 7/2 hours = 40 × 7/2
= 140 km
(3 1/2hours = 7/2 hours)