Let M denote the mean proportional between 16 and 9 and let N denote the third proportional of 9 and 15 . Find the value of 5M + 3N . - Quantitative Aptitude MCQ Competitive Exam 2026 | ExamTest.live

mediumMCQCompetitive Exam2026Quantitative Aptitude

1 attempts0% success rate1 mark

Let M denote the mean proportional between 16 and 9 and let N denote the third proportional of 9 and 15 . Find the value of 5 M + 3 N .

Solution & Step-by-step Explanation

1) Find the mean proportional M between 16 and 9 : M = 16 \times 9 = 144 = 12 Find the third proportional N of 9 and 15 : \frac{9}{15} = \frac{15}{N} N = \frac{15 \times 15}{9} = \frac{225}{9} = 25 Calculate the value of 5 M + 3 N : 5 M + 3 N = 5 (12) + 3 (25) 5 M + 3 N = 60 + 75 = 135

Try it yourself before checking the explanation above.

Let M denote the mean proportional between 16 and 9 and let N denote the third proportional of 9 and 15 . Find the value of 5 M + 3 N .

300

125

135

225

Practice with timed mock tests and track your performance across Quantitative Aptitude.