Question 3 - Page 138 - Number Pyramids - Chapter 6 Class 8 - Algebra Play (Ganita Prakash II)

Transcript

Question 3 - Page 138 What about filling in the numbers in this pyramid? Where do we start? Let’s put the unknown values as variables a, b, c So, our pyramid becomes So, our equations are now 12 + a = b And, a + 8 = c And, finally b + c = 60 Putting values of b and c from (1) and (2) (12 + a) + (a + 8) = 60 12 + 8 + a + a = 60 20 + 2a = 60 2a = 60 – 20 2a = 40 a = 40/2 a = 20 Putting a = 20 in (1) 12 + a = b 12 + 20 = b 32 = b b = 32 Putting a = 20 in (2) a + 8 = c 20 + 8 = c 28 = c c = 28 So, our pyramid becomes