The factorial of any number greater than 4 ends in 0. This is because the factorial operation involves multiplying the number by all positive integers less than it. Once you reach 5, you're multiplying by a number that has a factor of 5 and a factor of 2, which gives a product ending in 0. Any further multiplication will still end in 0.

So, we only need to consider the factorials of 1, 2, 3, and 4.

1! = 1
2! = 2
3! = 6
4! = 24

Adding these up, we get 1 + 2 + 6 + 24 = 33.

So, the digit in the unit position of the integer 1! + 2! +3! + ….+121! is 3.

Therefore, the answer is A3.

Question

The factorial of any number greater than 4 ends in 0. This is because the factorial operation involves multiplying the number by all positive integers less than it. Once you reach 5, you're multiplying by a number that has a factor of 5 and a factor of 2, which gives a product ending in 0. Any further multiplication will still end in 0.

So, we only need to consider the factorials of 1, 2, 3, and 4.

1! = 1
2! = 2
3! = 6
4! = 24

Adding these up, we get 1 + 2 + 6 + 24 = 33.

So, the digit in the unit position of the integer 1! + 2! +3! + ….+121! is 3.

Therefore, the answer is A3.

Knowee AI · Accepted Answer

The factorial of any number greater than 4 ends in 0. This is because the factorial operation involves multiplying the number by all positive integers less than it. Once you reach 5, you're multiplying by a number that has a factor of 5 and a factor of 2, which gives a product ending in 0. Any further multiplication will still end in 0.

So, we only need to consider the factorials of 1, 2, 3, and 4.

1! = 1
2! = 2
3! = 6
4! = 24

Adding these up, we get 1 + 2 + 6 + 24 = 33.

So, the digit in the unit position of the integer 1! + 2! +3! + ….+121! is 3.

Therefore, the answer is A3.

The digit in the unit position of the integer 1! + 2! +3! + ….+121!Select an answerA3B4C5D6

Question

Solution

Similar Questions

Upgrade your grade with Knowee