Martin can read 4 pages in 7 min, at this rate how long will it take him to read 9 pages?

Answer 1

So this is a rate question. Martin reads 4 pages in 7 minutes. That means he reads 4/7 of one page per minute. 7 corresponds to the number of minutes, 4 responds to the number of pages. So when asked how long it takes to read 9 pages you set it up as

9/x = 7/4

Because there are 9 pages and you want to know how many minutes it will take.

When you have fractions in this fashion you can cross multiply.the entire equation by x leaving

9 = 7x/4

then you multiply the entire equation by 4 leaving

36 = 7x

Divide 36 by 7 and you get

x = 36/7 minutes or if your teacher prefers rounding to decimals 5.142857 minutes