If the third proportional of 8 and x is 98 . find the value of x
Answers
Step-by-step explanation:
Solved Examples For You
Part I
Example 1: Find the fourth proportional to 4, 9 and 12?
A) 18 B) 21 C) 24 D) 27
Answer: Let the fourth proportional to the numbers 4, 9, and 12 be x. Then from the definition of the fourth proportional, we must have:
4: 9 :: 12 : x or in terms of the fractions we can write;
4x = 9 × 12. In other words, we have x = {9 × 12}/4 = 27. Thus the correct option is D) 27.
Example 2: The third proportional to 16 and 36 will be:
A) 9 B) 27 C) 45 D) 81
Answer: Let the third proportional to the two numbers 16 and 36 be x. Therefore from the definition of the third proportional, we have:
16: 36 :: 36 : x or in other words we can write:
16x = {36 × 36}/16 = 81. Therefore the correct option is D) 81.
Example 3: Find the mean proportional between 0.08 and 0.18?
A) 0.12 B) 0.09 C) 0.12 D) 0.16
Answer: We have the two terms as 0.08 and 0.18. Let us find their square root first. We have sqrt{0.08 + 0.18} = sqrt{8/100 + 18/100} = 12/10 or 0.12. Thus the correct option here is C) 0.12.
Example 4: If we divide 76 into four parts proportional to 7, 5, 3, 4, then the smallest part is equal to:
A) 11 B) 12 C) 13 D) 14
Answer: The ratio that we have here 7: 5: 3: 4. Then the smallest part will correspond to the factor of ‘3’. The sum of the terms of the ratio = 7 + 5 + 3 + 4 = 19.
Hence the smallest part will be = [76×{3/19}] = 12. Hence the correct option is B) 12.