How would I do part d

If 20% of a number is 35, what is 50% of that number?

Ajar of gumballs contains 4 reds, 2 greens, and 6 blues. what is the probability of getting two blues in a row without replacement?

Atruck can be rented from company a $50 a day plus $0.60 per mile. company b charges $20 a day plus $0.80 per mile to rent the same truck. find the number of miles in a day at which the rental costs for company a and company b are the same