One plate of Jowar roti costs ₹ 30 and one plate of Pulao costs ₹ 20. If x plates of Jowar roti. Class 7

One plate of Jowar roti costs ₹ 30 and one plate of Pulao costs ₹ 20. If x plates of Jowar roti. Class 7

Question 1.

One plate of Jowar roti costs ₹ 30 and one plate of Pulao costs ₹ 20. If x plates of Jowar roti and y plates of pulao were ordered in a day, which expression(s) describe the total amount in rupees earned that day? Class 7

(a) 30x + 20y

(b) (30 + 20) × (x + y)

(c) 20x + 30y

(d) (30 + 20) × x + y

(a) 30x - 20y

Solution:

(a) 30x + 20y

Question 2.

'Pushpita sells two types of flowers on Independence day: champak and marigold. 'p' customers only bought champak, 'q' customers only bought marigold, and ‘r' customers bought both. On the same day, she gave away a tiny national flag to every customer. How many flags did she give away that day? Class 7

(a) p + q + r

(b) p + q + 2r

(c) 2 × (p + q + r)

(d) p + q + r + 2

(e) p + q + r + 1

(f) 2 × (p + q)

Solution:

(a) p + q + r

Question 3.

A snail is trying to climb along the wall of a deep well. During the day it climbs up ‘u' cm and during the night it slowly slips down ‘d' cm. This happens for 10 days and 10 nights. Class 7

(a) Write an expression describing how far away the snail is from its starting position.

(b) What can we say about the snail’s movement if d > u?

Solution:

(a) Expression = 10 × (u - d)

= 10u - 10d.

(b) If d > u, then the snail will move 10u - 10d

= 10 (M - d) = — 10 (d - u) (d > u)

So, the snail will be below the ground level. If there is no hole in the ground, then the snail will remain on the ground itself.