GMAT Basic Probability practice questions

A farmer is testing two new fertilizers on separate plots of soybeans. Plot A has a 70% chance of yielding at least 1,000 kg of soybeans, while Plot B has a 40% chance of yielding at least 1,000 kg. If the two plots' yields are independent, what is the probability that at least one of the plots yields at least 1,000 kg of soybeans?

A farmer plants two types of crops in separate fields: Field A and Field B. Field A yields 80 bushels of wheat per acre, while Field B yields 120 bushels of corn per acre. The farmer allocates 150 acres to Field A and 50 acres to Field B. What is the probability, rounded to the nearest hundredth, that a randomly selected bushel from the total harvest is wheat?

A farmer tests two new fertilizers on separate plots of corn. Fertilizer A increases the probability of a high-yield harvest from 40% to 60%. Fertilizer B increases it from 30% to 50%. The farmer selects one fertilizer at random to use on all his fields this season. What is the probability that he achieves a high-yield harvest?

A hospital lab processes blood samples in batches. Each batch contains 120 samples. Historically, 5% of samples require additional testing. To prepare for a potential surge, the lab manager wants to calculate the probability that at least 8 samples in a randomly selected batch will require additional testing. Which of the following best approximates this probability? (Note: The manager considers using both binomial and Poisson approaches in the calculation.)

A restaurant is testing a new menu item and wants to determine the probability that multiple customers will order it when presented with other options. In a survey of 1,200 customers, 480 ordered the new item. The manager wants to calculate the probability that, if five customers are selected at random, at least three of them ordered the new item. Which of the following is closest to this probability?