4)A tank is 20m in length, 15m in breadth and 4m in depth. Find the cost of cementing its floor and the four walls at the rate of Rs.50 per sq. m​

Ametalworker has a metal alloy that is 30? % copper and another alloy that is 55? % copper. how many kilograms of each alloy should the metalworker combine to create 90 kg of a 50? % copper? alloy?

When george started his current job, his employer told him that at the end of the first year, he would receive two vacation days. after each year worked, his number of vacation days will double up to five work weeks (25days) of payed vacation. how many vacation days will he have in 4 years

I’m still confused on how to work the percentages