Question

Brand X copier has improved its copier

so that it produces 24% more copies than its old model if the old model ran 351 copies per hour how many copies would the new model run

Answer 1

351 copies is the 100%, the old model. The new model is 100 + 24 %, so 124%.
351 times 124 divided by 100 is the answer, 435,24 copies