a water tank had three inlets, which independently can fill the tank in 20,40,30 minutes, respectively. How much time does it take to fill the when all work together

What is the gcf of 20c^3-5c^4+30c^6

Would greatly appreciate these 3 answers

Nicolo paganini's numbers 1184 and 1210 are amicable. the proper divisors of 1184 are 1, 2, 4, 8, 16, 32, 37, 74, 148, 296, and 592. the proper divisors of 1210 are 1, 2, 5, 10, 11, 22, 55, 110, 121, 242, and 605. use the definition of amicable (friendly) numbers to show that they are indeed amicable. which of the folowing statement uses the definition of amicable numbers to show that 1184 and 1210 are indeed amicable? o a. o b. ° c. the sum of proper divisors of 1184 is 1210 and the sum of proper divisors of 1210 is 1184 the sum of proper divisors of 1184 is greater than 1210 and the sum of proper divisors of 1210 is greater than 1184 the sum of proper divisors of 1184 is less than 1210 and the sum of proper divisors of 1210 is less than 1184