NCERT Exemplar Solutions
Class 7 - Mathematics - Unit 7: Comparing Quantities - Problems and SolutionsQuestion 116
Class 7 - Mathematics - Unit 7: Comparing Quantities - Problems and Solutions
Question. 116
Health Application: A doctor reports blood pressure... Refer to the table of blood pressure ranges for adults. Manohar is in the normal category.
(a) Calculate an approximate ratio of systolic to diastolic blood pressures in the normal range.
(b) If Manohar’s systolic blood pressure is 102 mm Hg, use the ratio from part (a) to predict his diastolic blood pressure.
(c) Calculate ratio of average systolic to average diastolic blood pressure in the prehypertension category.
Answer:
(a) 3 : 2
(b) 68 mm Hg
(c) 259 : 169
Detailed Answer with Explanation:
(a) Approx normal = 120/80 ≈ 3:2.
(b) Diastolic = 102 × (2/3) = 68 mm Hg.
(c) Average systolic = (120 + 139)/2 = 129.5. Average diastolic = (80 + 89)/2 = 84.5. Ratio = 259:169.