Quantitative Aptitude - Arithmetic Ability Questions

The average height of 50 bats is 126 cm. Some bats of average height 120 cm are removed. If the new average height is 130 cm, then how many bats are remaining?

If x + [1/(x + 7)] = 0, then what is the value of x – [1/(x + 7)]?

If 4x - 5y = -37 and 7x + y = -16, then x - y = ______

If 5/2 - (6/5)(x - 15/2) = -x/5, then what is the value of x?

Which of the following equations has the sum of its roots as 11?

In ΔPQR, S and T are points on side PQ and PR respectively. ST is parallel to QR. If S divides PQ in the ratio 4:1 and length of QR is 15 cm,what is the length of ST?

Two men are on opposite sides of a tower. They measure the angles of elevation of the top of the tower as 30 ̊ and 45 ̊ respectively. If the height of the tower is 50 m, the distance between the two men is (Take √3 = 1.73)

Two students appeared for an examination. One of them secured 16 marks more than the other and his marks were 75% of the sum of their marks. The marks obtained by them are