Question

Ahmed spent 1/3 of his money on a burrito and a water bottle. The burrito cost 2 times as much as the water. The burrito cost $4. How much money does Ahmed have left?

Answer 1

Ahmed have left $12

Explanation:

Ahmed spent 1/3 of his money on a burrito and a water bottle.

The burrito cost 2 times as much as the water.

The burrito cost $4 and 2 times as much as the water, so, the water is the burrito cost divided by 2 ,

Water=$4/2=$2

So, water + burrito =$2+$4=$ 6

This $ 6 is 1/3 of the money, Ahmed have left 2/3 of the money ( 1- 1/3)

We use cross-multiplication

a/b=c/d

$6/(1/3)= ?/(2/3)

?=$6 x(2/3)/(1/3)

Dividing two fractions is the same as multiplying the first fraction by the reciprocal (inverse) of the second fraction.

Take the reciprocal of the second fraction by flipping the numerator and denominator and changing the operation to multiplication. Then the equation becomes

?=$6 x(2/3)x(3/1)= 6x2x3/ (1x3x1)=36/3=

?=$12

Answer 2

Ahmed's left with $12

Explanation:

step 1

Find out the cost of a water bottle

Let

x -----> the cost of a water bottle

y ----> the cost of the burrito

`y=2x` -----> equation A

`y=4` -----> equation B

substitute equation B in equation A and solve for x

`4=2x`

`x=2`

therefore

The cost of a water bottle is $2

step 2

Find out how much money does Ahmed have left

Let

x -----> the amount of money Ahmed originally had

we know that

The cost of a burrito and a water bottle is equal to one third of the amount of money Ahmed originally had

so

`4+2=(1)/(3)x`

Solve for x

`6=(1)/(3)x`

Multiply by 3 both sides

`x=18`

therefore

The amount of money Ahmed originally had was $18

If he spent 1/3 of his money

then

He's had 2/3 of the money left.

Multiply 2/3 by the amount of money Ahmed originally had

`(2)/(3)(18)=\$12`

therefore

Ahmed's left with $12.