Okay, so there's a number rounded to the nearest million, in this case 2 million. So this tells me that the number of visitors is between 1,500,000 and 2,499,999. The reason why 1,499,999 doesn't count is because the hundred thousands digit is not 5 or above, so it doesn't count. It would round down to 1 million, not 2 million. The reason why 2,500,000 doesn't count, is because the hundred thousands digit is 5, so that rounds to 3 million, not 2 million. The greatest number of visitors that visited the aquarium has to be 2,499,999, because that's one digit away from 2.5 million, and the hundred thousands digit is a 4, not 5. The answer is 2,499,999
In 'n' 10! ways, books can be arranged. But, there are also 5! permutation of blue books 'n1', 2! permutation of identical green books 'n2', and 3! permutation identical black books 'n3'.
Therefore, for non identical arrangements:
= 2520
Therefore, the books can be arranged on a shelf in 2520 patterns
To find the surface area of a right cone, we can use the following formula:
,
where:
• r = radius
• l = slant height.
In the question, we are told that the diameter of the cone is 30 in. Therefore its radius is (30 ÷ 2 = ) 15 in. We are also told that its height is 8 in.
Using this information and the formula above, we can calculate the surface area of the cone: