the food in a camp lasts for 10 men for 20 days . if 30 more men join , how many days will the food last ?
"one man can consume the same food in 10 * 20 = 200 days . 30 more men join , the total number of men = 40 the number of days the food will last = 200 / 40 = 5 days . answer : c"
divide(multiply(10, 20), add(10, 30))