Here’s and example of a **SMART MATH** problem for **ALGEBRA.**

**Problem**

**Problem**

Tom is 6 years elder to Dick. 20 years ago, Tom was 15 times older than Harry, but now Dick is twice as old as Harry. What is the age of Dick?

- 44
- 48
- 50
- 52
- 54

**The Usual Method**

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Let the present age of Dick be ‘*x*’ years.

Hence, age of Harry = years.

Age of Harry 20 years ago =

Present age of Tom =

Age of Tom 20 years ago =

years

**(Ans: 1)**

*Estimated Time to arrive at the answer = 45 seconds.*

**Using Technique**

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Assume each option to be the right answer and reverse calculate to check as follows:

Option Age of Dick Age of Tom Age of Tom 20 years back

a. 44 50 30 (multiple of 15)

b. 48 54 34 (not a multiple of 15)

c. 50 56 36 (not a multiple of 15)

d. 52 58 38 (not a multiple of 15)

e. 54 60 40 (not a multiple of 15)

(Note: If you go sequentially taking one option at a time and start with option ‘1’, you do not have to go further as option ‘1’ will give the age of Tom 20 years back as a multiple of 15. No other option leads to a multiple of 15.)

**(Ans: 1)**

*Estimated Time to arrive at the answer = 30 seconds.*

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