a bag contains 7 green and 8 white balls. if two balls are drawn simultaneously, the probability that both are of the same colour is -.
Answers
A) 7 / 18
B) 7 / 19
C) 7 / 11
D) 7 / 12
E) 7 / 15
<gadget id="calculator">7 + 8</gadget>
<output>15</output>

<gadget id="calculator">8 / 15</gadget>
<output>8/15 = around 0.533333</output>

<gadget id="calculator">8 - 1</gadget>
<output>7</output>

<gadget id="calculator">15 - 1</gadget>
<output>14</output>

<gadget id="calculator">7 / 14</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(8/15) * (1/2)</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">7 / 15</gadget>
<output>7/15 = around 0.466667</output>

<gadget id="calculator">7 - 1</gadget>
<output>6</output>

<gadget id="calculator">6 / 14</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">(7/15) * (3/7)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(4/15) + (1/5)</gadget>
<output>7/15 = around 0.466667</output>

<result>E</result>
a bag contains 7 green and 8 white balls. if two balls are drawn simultaneously, the probability that both are of the same colour is -.
add(multiply(divide(8, add(7, 8)), divide(subtract(8, const_1), subtract(add(7, 8), const_1))), multiply(divide(7, add(7, 8)), divide(subtract(7, const_1), subtract(add(7, 8), const_1))))
"drawing two balls of same color from seven green balls can be done in ⁷ c ₂ ways . similarly from eight white balls two can be drawn in ways . 7 / 15 answer : e"