if u buy 21 pencils with some money and if that money is increased by 40% how many pencils can u buy
let M be the money,
M 1.4M
_ = ____ cross multiply and solve for n
21 N
MN = 21* 1.4 M divide M out of both sides
n = 1.4 * 21 = 29 round down to a whole number. We can't buy parts of pencils.