7. En una reunió de nois i noies el nombre de noies és 25 vegades més que el de nois. Si surten de la reunió 10 nois i 10 noies, queden el doble de noies que de nois. Quants nois i quantes noies hi havia inicialment a la reunió?

Initially 100 milligrams of a radioactive substance was present. after 6 hours the mass had decreased by 4%. if the rate of decay is proportional to the amount of the substance present at time t, find the amount remaining after 24 hours. (round your answer to one decimal place.)

Write the fraction 9/50 as a decimal if needed round to the nearest hundredth

Ijust need to see how to do this. so you don’t have to answer all of them just a step by step explanation of one.