3 years ago, the average age of a, b and c was 27 years and that of b and c 5 years ago was 20 years. a ’ s present age is:	Choices:
A) 22
B) 88
C) 40
D) 87
E) 17
<gadget id="calculator">27 * 3</gadget>
<output>81</output>

<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<gadget id="calculator">81 + 9</gadget>
<output>90</output>

<gadget id="calculator">20 * 2</gadget>
<output>40</output>

<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<gadget id="calculator">40 + 10</gadget>
<output>50</output>

<gadget id="calculator">90 - 50</gadget>
<output>40</output>

<result>C</result>
3 years ago, the average age of a, b and c was 27 years and that of b and c 5 years ago was 20 years. a ’ s present age is:
subtract(add(multiply(27, 3), multiply(3, 3)), add(multiply(20, const_2), multiply(5, const_2)))
explanation : sum of the present ages of a , b and c = ( 27 × 3 + 3 × 3 ) years = 90 years . sum of the present ages of b and c = ( 20 × 2 + 5 × 2 ) years = 50 years . a ' s present age = 90 – 50 = 40 years . answer : c