(i) Let sugar crystals be x.

Weight of sugar (in kg) 2 5
No. of crystals 9×10⁶ x
Here weight of sugar and number of crystals are in direct proportion.
∴ 2x/9×10⁶ = 5/x ⇒ xX2=5x9x10⁶ ⇒ x=5x9x10⁶/2 = 22.5×10⁶ =2.25×10⁷
Hence, the number of sugar crystals is 2.25×10⁷.

(ii) Let sugar crystals be x.
Weight of sugar (in kg) 2 1.2
No. of crystals 9×10⁶ x

Here weight of sugar and number of crystals are in direct proportion.
∴ 2/9×10⁶ = 1.2/x ⇒ xX2=1.2x9x10⁶ ⇒ x=1.2x9x10⁶/2 = 0.6x9x10⁶=5.4×10⁶
Hence, the number of sugar crystals is 5.4×10⁶.

Class 8 Maths Chapter 11 Exercise 13.1 Solution in Video

for more answers vist to:
https://www.tiwariacademy.com/ncert-solutions/class-8/maths/chapter-13/