Problem Solving

Hey Guys,

Is there any short cut method availalbe to answer the following simple question ?

What is the greatest integer that is a sum of four different prime numbers, each less than 30 ?

A 67
B 88
C 98
D 104
E 126

I narrowed down the options to A,B,C,D and ignored option E as it is over 120. Answered the question by summing up different prime numbers which are less than 30. I am sure that there must be a smarter approach to solve this question.

not sure how to do it faster... but even if you just sum up the 4 primes, it shouldn't take more than 1 min.

count down from 30 to find the highest 4 primes, sum those = answer.
29, 23, 19, 17=88

I think, no need to use POE for this kind of problems. Solving directly is the simple & less time consuming way.

I think you have solved the right way.

It is difficult to deduce any formulae for it. Its better to count n add 29+23+19+17=88.

Cheer up

Sometimes we can out-think ourselves when trying to come up with a neat "trick". As has been mentioned, take the 45 seconds or so and focus energies on getting the 4 greatest prime numbers less than 30 accurately.