Packet X contains pens, pencils and erasers in the ratio 1:2:3. Packet Y contains pens and pencils in the ratio 4:5. If the total number of pens and pencils in both the packets combined is 13 and 20 respectively, what is the number of erasers in Packet X?
A perfect cake should have 25% cream and 75% bread. Oman bought material for a 5kg cake with 35% cream and 65% bread. How many more kg of bread should he buy if he wants to make a perfect cake?