Question

The average weight of 10 boys is more than the average weight of 15 girls by 5 kg. If the total weight of the 10 boys is 550 kg, what is the average of the 10 boys and 15 girls together? [February 28, 2015 @ 40m 30s] 1) 52 kg 2) 52.5 kg 3) 53 kg 4) 43.5 kg 5) None of these

Answer 1

average weight of 10 boys = 550/10 = 55 kgaverage weight of 15 girls = 55-5 = 50 kgaverage weight of 10 boys and 15 girls = (10*55+15*50)/(10+15)
                                                                 = (550+750)/25
                                                                    = 1300/25
                                                                        = 52kg

Answer 2

Answer:

52 kg

Step-by-step explanation:

The total weight of the 10 boys is 550 kg,

$\text{Average Weight of boys} =\frac{\text{Total weight of 10 boys}}{\text{Number of boys}}$

$\text{Average Weight of boys} =\frac{550}{10}$

$\text{Average Weight of boys} =55$

Now we are given that The average weight of 10 boys is more than the average weight of 15 girls by 5 kg.

So, The average weight of 15 girls is 55-5=50 kg

$\text{Average Weight of Girls} =\frac{\text{Total weight of 15 Girls}}{\text{Number of Girls}}$

$50 =\frac{\text{Total weight of 15 Girls}}{15}$

$50 \times 15  =\\text{Total weight of 15 Girls}$

$750  =\\text{Total weight of 15 Girls}$

So, Total weight of 15 girls = 750

Now  the average of the 10 boys and 15 girls together

$\text{Average of the 10 boys and 15 girls together} =\frac{550+750}{15+10}$

$\text{Average of the 10 boys and 15 girls together} =52$

So, Option 1 is true .

Hence the average of the 10 boys and 15 girls together is 52 kg