The price of a math book is $50, but you have only $35 with you. if you get a discount of 20%, how much money do you need to borrow from a friend so that you can buy the book?

Price of the book = $50

20% discount = 0.2 x 50 = $10

After discount, the price of the book is
$50 - $10 = $40

I have $35, so I need
$40 - $35 = $5 more

I need to borrow $5 from a friend.

You can find the area of a rectangle by multiplying the length and height. so multiply 1/2*7/4(which is the simpler version of 1 3/4) and you get 7/8 as your answer.