Ronnie, Sulaiman and Ted each had some marbles. Ronnie gave Sulaiman some marbles that doubled the number of marbles he had. Then Sulaiman gave some marbles to Ted that doubled the number of marbles Ted had. Finally, Ted gave Ronnie some marbles that doubled the number of marbles Ronnie had. The number of marbles Ronnie, Sulaiman and Ted had became 168, 136 and 144 respectively. Find the number of marbles each child has at first.
Ronnie went to 3 shops with some money. In the first shop, he spent $8 more than half the money he had. In the second shop, he spent the $6 less than half the remaining money. In the third shop, he spent $30, and he was left with $25. Find the original amount of money he had.
In the library, there are 750 books on a particular cabinet. A librarian case to reshuffle the books between the two shelves. 30 books are removed from the top shelf to the second shelf. Another 80 books are put in the second shelf. In the end, there are 4 times as many books in the second shelf as in the first shelf. How many books are there in the second shelf at first?
A rope is being cut in such a way, in the first cut, 3 m less than half the length is cut away. In the second cut, 5 m more than the remaining half of the rope is cut away. There is 10 m left. Find the original length of the rope.