Quantitative Aptitude - Arithmetic Ability Questions

In a motor of 120 machine parts, 5% parts were defective. In another motor of 80 machine parts, 10% parts were defective. For the two motors considered together, the percentage of defective machine parts were

If x – y – √18 = –1 and x + y – 3√2 = 1, then what is the value of 12xy(x2 – y2)?

In the following question, four number pairs are given. The number on left side of (–) is related to the number on the right side of (–) with some Logic/Rule/Relation. Three are similar on basis of same Logic/Rule/Relation. Select the odd one out from the given alternatives.

If the three numbers in the ratio 3:2:5 be such that the sum of the squares is equal to 1862 then which number is the middle one.

The ratio of three numbers is 2 : 5 : 7. If their product is 1890, then what is the sum of the three numbers?

Find the value of 777777?

There are total 200 students in a school, of which 1/5th are boys. Find the number of girls in the school.

In the given figure, from the point P two tangents PA and PB are drawn to a circle with centre Oand radius 5 cm. From the point O, OC and OD are drawn parallel to PA and PB respectively. If the length of the chord ABis 5 cm, then what is the value (in deg) of COD?