Madame curie made some radium in her lab. she used 2/5 kg of the radium in an experiment and had 1 1/4 kg left. how much radium

Question

evablogger [386]

2 years ago

6

Madame curie made some radium in her lab. she used 2/5 kg of the radium in an experiment and had 1 1/4 kg left. how much radium

did she have at first?

Mathematics

2 answers:

jasenka [17] · Answer 1 · 2022-07-20T06:27:35+03:00

jasenka [17]2 years ago

8 0

SHE HAD 3/5 TO START I BELIEVE

Marina86 [1] · Answer 2 · 2022-07-20T08:48:40+03:00

Madame Curie had $1\frac{13}{20}$ kg of radium at the beginning.

<h3>Further Explanation</h3>

Madame Curie used ²/₅ kg for experiment

Radium left = 1¹/₄ kg

<u>Question:</u>

How much radium did she have at first?

The amount of radium that Madame Curie had at first :

= Radium for experiment+ the amount of radium left

$\boxed {= \frac{2}{5} + 1\frac{1}{4} }\\$

we can do the additional if the denominator is the same, if not we need to find a common denominator, in this problem, the common denominator for 5 and 4 is 20, so the equation would be:

we change the mixed fraction into an improper fraction

$\boxed {=\frac{2}{5} + 1\frac{1}{4} } \\\boxed {=\frac{2}{5} + \frac{5}{4} =( \frac{2 \times4}{5 \times4}) + (\frac{5 \times5}{4 \times5}) } \\\boxed {= \frac{8+25}{20} =\frac{33}{20} = 1\frac{13}{20} }$