Explanation

Ratio of Math : Physics : Chemistry = 3 : 4 : 5

Total parts = 3 + 4 + 5 = 12 parts

Total marks = 84,000

Value of 1 part = 84,000 / 12 = 7,000

Marks in Physics = 4 parts = 4 * 7,000 = 28,000

Last verified on 03-09-2026

Explanation

Explanation

Given ratio:

Copper : Silver = 3 : 5

Step 1: Find the total parts:

3+5=8

Step 2: Silver represents 5 parts out of total 8 parts.

Fraction of Silver = Silver parts/Total parts

=5/8

$$\text{<br>}$$$$=frac{5}{8}$$

Explanation

Given:

a:b = 8:9,

b:c = 6:5

Make b equal in both ratios. LCM of 9 and 6 = 18.

a:b=8:9=16:18

b:c=6:5=18:15

So, a:b:c = 16:18:15

Explanation

Step 1: Assistant A

24 records in 18 minutes

Rate = 24 / 18 = 1.333 records per minute

In 40 minutes = 1.333 x 40 = 53.33

Exclude fraction = 53 complete records

Step 2: Assistant C

20 records in 16 minutes

Rate = 20 / 16 = 1.25 records per minute

In 40 minutes = 1.25 x 40 = 50

Exclude fraction = 50 complete records

Step 3: Total

53 + 50 = 103 complete records

Answer: 103 records, being 53 and 50 with fractions disregarded.

Last verified on 10-09-2026