Example 8 - Chapter 7 Class 7 - Finding the Unknown (Ganita Prakash II)

Transcript

Example 8 Madhubanti wants to organise a party. She decides to buy snacks for the party from the chaat shop in town. Each plate of snacks costs ₹25. The shop charges an additional fixed amount of ₹50 to deliver the snacks to Madhubanti’s house. There are 5 members in Madhubanti’s family, including herself. Her parents tell her she can spend ₹500 on this party. How many friends can she invite to the party if she wants to give a plate of snacks to each person, including her family and friends?Given Total Budget: ₹500 Fixed Delivery Charge: ₹50 and Cost per plate: ₹25 Family members: 5 Let f be the number of friends. Thus, Total people in party = (f + 5) Now, she can spend ₹ 500 on the party So, we can write Amount spent = Cost per plate × Total people + Delivery cost Putting values 500 = 25 × (f + 5) + 50 Taking 50 on left side, so it gets subtracted 500 – 50 = 25 × (f + 5) 450 = 25 × (f + 5) Taking 25 on left side, so it gets divided 450/25 = f + 5 18 = f + 5 f + 5 = 18 Taking 50 on left side, so it gets subtracted f = 18 – 5 f = 13 Thus, she can invite 13 friends