Fill in the blanks. (i) If 3 persons can do a piece of work in 4 days, then 4 persons can do it in……days. (ii) If 5 pipes can fill a tank in 144 minutes, then 6 pipes can fill it in ……minutes. (iii) A car covers a certain distance in 1 hr 30 minutes at 60 km per hour. If it moves at 45 km per hour, it will take……hours. (iv) If 8 oranges cost Rs. 20.80, the cost of 5 oranges is Rs…… (v) The weight of 12 sheets of paper is 50 grams. How many sheets will weigh 500 grams?

Question

Fill in the blanks. (i) If 3 persons can do a piece of work in 4 days, then 4 persons can do it in&#x2026;&#x2026;days. (ii) If 5 pipes can fill a tank in 144 minutes, then 6 pipes can fill it in &#x2026;&#x2026;minutes. (iii) A car covers a certain distance in 1 hr 30 minutes at 60 km per hour. If it moves at 45 km per hour, it will take&#x2026;&#x2026;hours. (iv) If 8 oranges cost Rs. 20.80, the cost of 5 oranges is Rs&#x2026;&#x2026; (v) The weight of 12 sheets of paper is 50 grams. How many sheets will weigh 500 grams?

Philoid · Accepted Answer

(i) By Inverse proportion

3 × 4 = 4 × (no. of days required)

(No. of days required) = = 3 days

(ii) By Inverse proportion

5 × 144 = 6 × (time required)

(Time required) = = 120 minutes

(iii) By Inverse proportion

90 minutes × 60 km/hr = 45 km/hr × (time taken in minutes)

(No. of days required) = = 120 minutes = 2 hours

(iv) More the oranges more will be the cost. So it is a direct proportion.

Let the cost be Rs x,

⇒ 8 × x = 20.80 × 5

x = = Rs 13

(v) More the no. of sheets more will be the weight of them. So it is a direct proportion.

Let the no. of sheets be x,

50 × x = 500 × 12

x = = 120 sheets