1.Three men went to a hotel to rent a room, the cost of the room was $30. Each man paid $10 to the bellboy and proceeded to their room. After a little while the bellboy realized that there was a special on rooms that night and the price for the men’s room should have been $25. On his way to the men’s room to give them back $5, he was puzzled how he was going to split $5 as he had no change. He decided he would give them each $1 and keep the remaining $2 for himself. So each man originally paid $10, but after the bellboy gave each man $1 back, each man paid $9. 9 x 3 = $27 plus the $2 the bellboy put in his pocket equals $29. The original price for the room was $30. Where did the last dollar go?
2.How many 3 digit numbers have no repeated digits?
3.10. Every month, a girl gets allowance. Assume last year she had no money, and kept it up to now. Then she spends 1/2 of her money on clothes, then 1/3 of the remaining money on games, and then 1/4 of the remaining money on toys. After she bought all of that, she had $7777 left. Assuming she only gets money by allowance, how much money does she earn every month?
Those are some random math problems, tho the 1st one is…hard.
Hraesvelg: The final dollar goes to pay the bills of staying.
25 dollars is the sum they paid to stay at the room. 2 dollars they paid to the bellboy.
Therefore, a total of 27 dollars was being paid by them. 27/3 = 9. You shouldn’t have added two to the sum they paid - Since they have already paid it!
[spoiler]The possibility for two repeated digits is, the 1° and the 2° (xxy), the 1° and the 3° (xyx), the 2° and the 3° (yxx);
First case: the 1° digit (the hundreds one) has 9 possibilities (from 1 to 9), the 3° one is free and can be 10 numbers (0-9), so it’s 910=90 numbers
Same with the second case: 90 numbers.
For the third case, first digit can be 9 numbers, the other two can be 10, so it’s still the same: 910= another 90 possibilities.
But wait! We counted the single-digit numbers three times! (111, 222, etc.) so we must subtract 9*2=18 to the sum, making 90+90+90-18=252 numbers.
The remaining ones are therefore (999-100+1) - 252 = 900 - 252 = 648.[/spoiler]
Problem 3:[spoiler]After spending on clothes, she has half the money left; after games, it’s 1/2 - (1/2 * 1/3) = 1/3; after toys, it’s 1/3 - (1/3 * 1/4) = 1/4 money left.
So it’s x/4=7777, so x = 21108, where x is yearly allowance. To get a single month, we do x/12= 7777/3 = 2592,33.[/spoiler]
the gravitational pull of a planet compared to earth is 3:8 or 3/8 a new moon starts to orbit the other planet making the gravitational pull 5x stronger what is the new ratio? it took me a while to figure that out myself
(Let’s just say that 1g = 9.8 m/s^2 instead. That is equal to 9.8 newtons of force per square kilogram. )
You drop a 1000kg object from 1km high. If it were to fall at a steady rate of 9.8 meters per second, how much force will it undergo when it hits the ground?
Well, Infinity, subtracted by itself, should be zero.
Because even though it is unlimited, no further numbers exist.
So even though Infinity + 5 = Infinity, Infinity = Infinity, never something greater, because nothing greater exists. So just treat Infinity like a number.
So Infinity - Infinity = 0.
If it is true, Infinity - Infinity - Infinity = -Infinity, because 0 - Infinity = -Infinity.