Question

Liang went to the bookstore. he spent 1/3 of his ,money on a pen and 4/7 of it on books. what fraction of his money did he have left?

Answer 1

Convert into like fractions --> 
1/3 = 7/21 4/7 = 12/21
7+12 = 19
19/21 is spent therefore he has 2/21 left

Answer 2

The fraction of the amount Liang has left is $\frac{2}{21}$

• Let X = Amount spent on a pen; X = $\frac{1}{3}$
• Let Y = Amount spent on books; Y = $\frac{4}{7}$
• Let M = Amount of money Liang has got; M =?
• Let L = Amount of money Liang will have left; L = ?

Further Explanation

To derive L (amount of money Liang will have left), add X (amount spent on a pen) and Y (amount spent on books) together, then the derived value be subtracted from M (fraction of total amount Liang has got) i.e.: M – (X + Y)

Therefore, L = M – (X + Y)

Deriving (X + Y)

= X + Y

= $\frac{1}{3}$ + $\frac{4}{7}$

= (1 x 7) + (3 x 4) / 21

= (7) + (12) / 21

= 7 + 12 / 21

= $\frac{19}{21}$

X + Y = $\frac{19}{21}$

Since the lowest common denominator of the fraction of X and Y = 21, then the fraction of M = $\frac{21}{21}$

Thus, M = $\frac{21}{21}$

Recall, L = M – (X + Y)

Thus,

L = $\frac{21}{21}$ – $\frac{19}{21}$

L = (1 x 21) – (1 x 19) / 21

L = (21) – (19) /21

L = 21 – 19 /21

L = $\frac{2}{21}$

Hence, the amount Liang will have left is $\frac{2}{21}$

LEARN MORE:

• Numbers: brainly.com/question/2906770
• mixed numbers brainly.com/question/12853142
• fraction brainly.com/question/6201432

KEYWORDS:

• denominator
• numerator
• numbers
• fraction
• liang