Question

A number 28 is divided into four parts that are in AP such that the product of the first and fourth is to the product of the second and third is 5: 6. Find the smallest part. 

(a) 2 

(b) 4 

(c) 8 

(d) 6

Answer 1

Correct option (b) 4

Explanation:

Since the four parts of the number are in AP and their sum is 28, the average of the four parts must be 7. Looking at the options for the smallest part, only the value of 4 fits in, as it leads us to think of the AP 4, 6, 8, 10. In this case, the ratio of the product of the first and fourth (4 × 10) to the product of the first and second (6 × 8) are in 5: 6 ratio.