Math problem

Question

Wilfredo buys 2/5 pound of mixed nuts for $2.50 . At this rate, how many pounds of mixed nuts can he buy for $10?

Answer 1

$10/$2.50=4

4*(2/5)=8/5=1 3/5 pounds or 1.6 pounds

you could set up a proportion

(2/5)/2.5=n/10

cross multiply

(2/5)(10)=(2.5)(n)

4=2.5n

40=25n

n=40/25

n=1 15/25

n=1 3/5 again

Answer 2

Use the information you do know to draw a picture. We know that each 2/5 is $2.50 and we know he buys a total of $10, so I write $2.40 four times to equal his total of $10. Next, I label each $2.50 with 2/5 pound. Now, I need to add my pounds to find the total pounds. 

 

$2.50 + $2.50 + $2.50 + $2.50 = $10

  2/5  +    2/5 +     2/5 +    2/5 =   ?

 

Add the numerators (the top of the fraction) 2+2+2+2 = 8

The denominator (the bottom of the fraction) stays the same = 5

 

8/5 is an improper fraction, so we need to simplify. 

 

5/5 is one whole which we write as "1". That leaves 3/5 left (8-5=3).

 

Our answer is 1 and 3/5 pounds of mixed nuts purchased.