Hi


please help me with the question. I need explanations to the answer too.

Alfred and Benedict were given some money each, If Alfred spent $45 each week and Benedict spent $90 each week. Alfred would still have $ 840 left when Benedict spent all his money. If Alfred spent $90 each week and Benedict spent $45 each week. Alfred would still have $210 left when Benedict has spent all his money.
a) How much money did Alfred receive?
b) How much money did Benedict receive?

Terry and Alex have some marbles each. When Terry losed 4/9 of his marbles to Alex, the ratio of Terry’s marbles to Alex’s marbles becomes 2:3.
a) What is the ratio of Terry’s mables to Alex’s marbles at first?
b) Terry plays an other games with Alex and loses 35 marbles to Alex and the ration of Terry’s marbles to Alex’s marbles becomes 1:4. Calculate the number of marbles Terry have in the end.